I have the same problem with Tiger.  He will let me comb him but the
mats seem to form anyway.  It's best to bite the bullet and let the vet
clip the mats out.

                 -MIKE

You seem to be asking for a miracle and have eliminated almost all options.
You must either:

A) Find a way to get him to enjoy brushing at home

B) Take him to a vet to have the mats removed.  If he's an indoor cat you
can get what's called a "lions cut" in which they will completely shave him
(except for head, feet and tail) so you can start from scratch.

or

C)  Don't brush him, and don't take him to the vets.  It seems to me you are
leaning towards option C.

Kelly

Have you tried to sneak it in while petting him, at first? Maybe wait until
he is sleepy and lying near you wanting his head scratched, and introduce
the brush that way. Once he gets used to it you might be able to get at the
snarled parts.

Hi Angi,

I guess approaching when he's half asleep hasn't worked?

You could try grinding up a sedative in his food and see if that
mellows him out a bit, but make sure that you clear with the vet what
you're giving him.

Have you tried just working the mats a bit with your fingers? I know
it can be a bit gross in the butt area, but sometimes if I can't get
my Maine Coon mix to sit still for a brushing, I can do some
unknotting in a sensitive spot with my hand while petting with the
other hand (usually a belly rub). Eventually she figures out what I'm
doing - LOL, but I can make slow steady progress on the matts over a
couple of days.

But if the matts are really severe than you may need to either get the
hair trimmed back there on a regular basis, or pay the vet to do a
periodic cleanup.

Sound a lot like my cat, Ruf.   What I do is go ahead and comb him.  I
start at the head and down the back, which he likes.  When I get to
where the matts are and the comb catches in them, I just go ahead and
pull.  Yes, it hurts him; he growls cries, screams, and tries to bite,
but I keep working on it as long as is reasonable.

Ruf seems to like the result because he comes to me and asks for it,
often nosing the comb in my shirt pocket.  I suspect that the mats
pull at his skin in the rump area, and he recognizes that with the
mats gone, the discomfort goes away.  I've had him shaved by the vet,
but that was only a very temporary solution.  

Just our results in our 11-year relationship.

Jerry