I tried it on Storm and it helped stop his inappropriate peeing right away and also helped with his aggressive behavior. It did change his personality though and he became very paranoid and would just sleep most of the time. I then decided to stop using it and my vet said that I had to wean him off of it so I did. He was on the liquid kind and he was getting .3ml 1 time a day. He hated the taste even though it was tuna flavored.

My vet said that I should give him a 4-6 week trial on it but I noticed that he stopped peeing inappropriately right away. This is what my vet said about it:

Clomicalm is a tricyclic antidepressant, so can have alot of effects
on personality. More so, in general, then prozac--which is more of an
anxiolytic. Just about all psychoactive drugs that I am aware of have
been shown to NOT be effective as transdermal preparations (the cream
on the ear you mentioned), so I am surprised some find it effective.
None of these drugs are a magic bullet, please do not treat them as
such.

That said, I have prescribed some clomicalm for Storm. You can pick
it up at Adobe tomorrow. We should give it a 4-6 week trial, as these
drugs require some time to reliably change the brain chemistry that
leads to behavioral changes. I would continue to use the feliway. He
may be tired the first few days. If tiredness lasts longer then a
few days, contact me and we will modify the dose.

Now he's on an herbal supplement that's helping him with his aggressive behavior and he's been using the litterboxes like a good boy. He's so much calmer now and he also has his personality back. He's on Calm Spirit Tea Pills and right now he gets 1 pill in the morning and 1 at night. In Feb. I'll probably be able to just give him 1 pill a day. It took about 1 month for it to kick in but now he's a much happier and calmer cat. I hope that something will work for your cats. Good luck.