OMG - that poor boy and poor you! He did have the urinary surgery, right?

When you say it's not fair to him, I think what I can guess is in your mind somewhere, though no one wants to say it.

A wild guess - but if his UT problems are at all connected to stress and some other critters being around, I wonder if he could be temporarily fostered in a one-cat home (with a person he knows) to see if it helps.

And then there is Clomicalm, which Medusa swears by. A low daily dose might well work out less expensively than numerous vet visits.

{{{{hugs}}}} and prayers for Pouncer.