Most certainly! There is unfortunately not a surgical option to stop a cat from urine-marking in the house. Spaying and neutering is the only surgical option to restrict marking behaviors, and even then it's not 100%.
I can start by telling you that you're going to want to get a behaviorist in the house to observe the cats and then direct your through a more hands-on change of arrangement of the furniture and the litter boxes, as online I'm not going to be able to fully cover some of the more important bits (such as the paces in your house that need the most arrangement, or the highest areas of stress). This is something that only a person coming into your house will be able to do. You can read about the different types of behaviorists and locate one in your area here:
The most important place to start is by having a urinalysis done on all the cats. I know you have four peeing, but in a household with four cats, if one develops a urinary tract infection and starts peeing in the house outside of the box, this can entice the other cats to do so. It may require medication for the cat with the UTI and a LOT of cleaning with an enzyme-based cleaner to get rid of the scent and keep them from urinating in the same places over and over again.
I have seen cats drench the floors trying to cover up the scent of one cat urinating in their territory due to one UTI.
Because all four of them may be urinating, there is most likely some behavior component to this, so the key to getting cats to stop urinating out of the house is to determine why they are urinating in the first place.
Cats mark as a means of communicating with other cats. So aside from medical reasons, we can usually narrow this down to either: your cats are having conflicts amongst each other, or your cats are conflicting with an outside cat.
This is where your behaviorist will come in. If this is a conflict with an outdoor cat, you're going to want to gear your efforts towards limiting the indoor kitties from having too much stimulation from the outdoor kitties. This means that the windows should be shielded to keep them from seeing each other, and doors should be closed to keep them from ogling through to the outside kitty world.
Discouraging outdoor kitties from coming into your yard can be done by creative use of a sprinkler system (if you see a kitty outside, turn on the sprinklers or hook them up to a motion sensor to get them started when someone walks on to a lawn) or even taking your own kitties outside on a leash to walk and mark their own outside territories.
You'll want to place perches up high near the windows so they feel they can peer down at the outside world, rather than being on the same level and trapped in with an outdoor kitty.
It's possible you may want to get the offender(s) on an anti-anxiety medication to help reduce the nervousness that tends to spur urine-marking around an outdoor cat.
Put the feliway diffusers in the area of the household where they seem to come into contact with outside world the most (favorite windows, doors, etc.). Again, the placement of things like perches and diffusers are going to be best directed by a behaviorist. It is their job to identify and help redirect these behaviors in the correct locations.
If the conflict is between the kitties themselves, this may be a bit more complicated. There are a LOT of things to be done to help eliminate tension between cats within the same household. A few of the more common ones:
Clean the box frequently: Some cats are extremely picky about digging in a litter box that has urine and feces inside. You may have to increase the frequency that you scoop the litter. If you do it once a day, try doing it twice or even three times. Some cats just prefer a REALLY clean box.
Buy another litter box: Cats are picky about where they pee and poop. They feel vulnerable when they are going potty, and sometimes they have preferences about which function they are doing where. Your cat might like to pee in one box, and poop in another. You can put a second (third, fourth, fifth - for four cats, you will want 8 total litter boxes) litter box in the same rooms where they are urinate on the floor to give them another "option" for their potty places.
Move the current litterbox: Sometimes cats will experience negative experiences while inside the litter box, such as loud noises, sudden movements, or other cats in the household stalking them while they are trying to go. They can associate these problems with the litter box itself, and may avoid urinating or defecating in those places at certain times. Moving the litter boxes to a different area might either eliminate the cause of the anxiety associated with the litterbox, and allow your cat to potty without anxiety.
Change litters: Cats have sensitive noses, and sometimes the perfumed litters cause them displeasure. If you have changed litters recently, your cat may also be reacting to the change. You can try using an unscented litter to see if this helps solve the issue, or switching back to your old litter if you had more success previously.
Covered versus uncovered: Some cats are made nervous by covered litter boxes. Some of them are made nervous urinating/defecating out in the open with uncovered litter boxes. If you've gotten a new litter box, it may be that your cat is reacting to the change. You might also try switching the litter box from a covered litter box to an uncovered one or vice-versa to see if she has more success in that area.
Scent associations: Cats have a VERY strong sense of smell. When you are cleaning your the urine stains, make sure you are cleaning with an enzymatic cleaner. You have to make sure you're not only cleaning the top areas, but also anywhere the urine might have soaked such as furniture pads, cushions, the bed mattress, and sheets with the spray. Urine tends to soak into things, and they are able to smell the remnants of the urine even if we can't, and think this is an okay place to potty.
Pet calming plug-ins: Feliway should be put in these in the areas you have litter boxes and other high-stress areas to keep your cats feeling relaxed and calm while they are in there. This creates an environment where your cats feel comfortable, and is more likely to potty.
Playtime: Cats that get agitated with each other need to be run ragged with playtime for an hour at least once a day to help reduce the natural tension that cats have amongst each other. Make sure each kitty gets a chance to play and run out the excess energy to minimize how much they are stimulated by each other.
Medication and indoor perches are also very viable options for cats who are nervous with each other and resort to peeing inside. A behaviorist will be able to tell you where perches are going to do the most good.
As you can tell by the above, there are SO MANY things to be done when you have a cat (or cats) urinating inside and then multiply that by the number of cats you have in your household. I know it starts to seem overwhelming.
Keep in mind that the above are even just very basic descriptions of things that MAY need to be adjusted and not necessarily be the one thing that does the trick.
Due to your situation with all four cats being in on the (un)fun, I really do think that the behaviorist is going to end up being your salvation. When people talk about pet therapy, they have the silly image of a pet on a couch talking about problems in their lives, but a true behaviorist won't go into "therapy", but will instead focus on helping you enrich the environment to redirect the undesirable natural behaviors. Having someone come into your home and point out exactly what needs to be changed based on direct observation of your cats may be a lifesaver for you, and spare you from having to go through trial and error to get the urination to stop.
I know I've hit you with a lot of text, so if you have more detailed questions about anything or you want to follow up on anything, please feel free to hit "reply" and get back with me. I have four kitties at home as well, and I know just how taxing such a situation can be.