Merry Christmas. Wondering if you can help with a grooming issue? Bogbastardkitten is a giant Siberian 8 month old fluffball (will try and find picture indicating hairiness). We have got him used to being groomed generally but he has what I can only describe as giant dreadlocks in his armpits They're not bothering him but they are big matts and need sorting. I have got a thing called a Matt Splitter but I don't know if that is enough.
TBH (as a past owner of persians) the quickest and kindest solution is to find a groomer willing to clip cats and ask them to shave his armpits. There is not really a fix for big knots because they go right down to the skin and cats have very thin skin. I have only found matt splitters to be useful for quite small knots.