Thanks for the answers to my questions although I'm sorry that I was off my computer when you responded back.
The fact that the abscess is open and draining is actually a good thing since, hopefully, the pus will be removed.
I do have a few suggestions which may help with this problem:
1. Soaking is a good thing to do but I'd suggest the use of Epsom Salts added to the water. This product can be found at human pharmacies or online. Soak for 5-10 minutes at least 2-3 times a day
2. Peroxide has actually been shown to retard healing so I might avoid its use. An alternative would be dilute, otc Betadine or Iodine (to the color of weak tea).
3. I don't typically wrap abscesses in cats since I want them open to drain; however if you're changing it regularly, then this may be fine.
4. I'm not sure if you meant that you were giving him oral antibiotics or if you were applying topical antibiotics to the wound when you bandaged it.
If the former, please let me know what antibiotic you're giving him and the dosage so that I can confirm that it's appropriate.
But, if he's not taking oral antibiotics, then I'd recommend them since the foot is swollen and there's an intense smell (which indicates infection).
Most antibiotics will require that a vet dispense them; however, you can purchase Amoxicillin intended for fish which is exactly the same drug which is given to cats (and dogs for that matter). http://www.fishmoxfishflex.com/index.php/fish-mox-amoxicillin-30-count.html
The dose for an average 10 lb cat would be 100-150 mg twice a day so you'd have to split the 250 mg capsules. Pull them apart over a white piece of paper and split the granules into two halves. Then sprinkle the granules into a small amount of wet food which, hopefully, he'll eat. You could also mix the granules with a small amount of water and then use a syringe or eye dropper to squirt it into his mouth where there's a small gap.
I typically advise giving antibiotics with food to avoid stomach upset.
5. If he's not showing improvement within a few days, then several thing may be going on:
a) His has a suppressed immune system secondary to Feline AIDS or Feline Leukemia
b) He may need stronger antibiotics than Amoxicillin
c) He may have what's known as an L-form bacteria which will only respond to Doxycycline or Minocycline.
Most cats are pretty amazing healers and I've seen some of the worst abscesses/infections heal just fine. Hopefully, this will be the case with him.
I hope this helps although, again, my apologies for the delayed reply. Deb