Where I live you can buy this coat conditioning liquid. It might not get rid of the mats there already but if your cat can deal with a wash, then that might help.

Need full on protective gear on to wash a couple of the kitties I've had. LOL
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Strangely it was the Persian and the Himalayan that were the worst. The moggies didn't mind the occasional wash as much.

I sure do know what you mean.