I would take a warm damp cloth and hold it in place for a few minutes to try to soften and gently remove it. You might have to have help holding your cat for this.. and often holding them by the scruff will keep them from wiggling too much.
If he has long hair, it would help to clip or cut the hair from around the area because often the hair will trap the feces and cause these plugs to form.
I hope this is helpful and please let me know if you have any additional questions.
You can add a little canned pumpkin to his food- a spoonful.. and that might help soften his stool. Were you able to remove the plug?
Vaseline is fine if he will take it. You can give him an enema with warm water. Just a teaspoon or two of warm water- don't use a fleet enema or any over the counter prepared enema with chemicals... just warm water.
If you don't have any luck tomorrow, you should take him to the vet for an enema...sometimes we have to sedate them to be able to remove all of the stool that has backed up.
I don't blame you for not wanting to try. It's certainly not advisable and they understandably don't cooperate.
I hope the tricks we discussed help!
found this while trying to find out how to give 14 year old Mr.Customeran enema...........Marian
Gave my cat an ENEMA last night...