My ragdoll was very knotty and although he would be ok with being brushed, he tended to get in a mess at his backend with knots and poo - lovely
Regular brushing will definately help with the matts and I just had to find a brush he liked. I would incorporate a bit of brushing in his 9pm cuddle time. He used to know he had them under his neck and would not leave them alone making himself sore. I would generally cut them out if they were too bad to brush, but make sure I wasn't pulling the skin or cutting anywhere near the skin, sort of cutting straight through the middle of the matt well away from the skin (only if it was huge and unbrushable) then the rest of it would untangle. He would tolerate that

I have 3 brushes, a soft nylon bristle one, a fine wire one and a plastic one, I had been using the wire one as the bristles just bend so it doesn't tug. Today I used the plastic one which is not at all flexible and gives the best brush, just now she's sleeping next to me and I used the soft nylon one after a minute she starts biting it and rolling over to attack it/me.

The advice you have been given is excellent. I have found that treats work so, so well. I'd start by giving her a treat to wet her apetite, then showing her the brush and treating again. Then I'd hold the brush in one hand and the teat in the other. This way she has to get close to the brush to get the treat that she wants. you can slowly progress this to jus tresting the brush on her back, one stroke, then a few more. If she'll only tolerate it for 30 seconds, let her run off after that and get rid of the built up anxiety. Then when she comes back, treat again and do a littl emore. Build up to a full grooming session, and try not to pull on the knots for the first while, as she will then associate the experience with a negative feeling, i.e, pain. Very frustrating I know because you want to get rid of them all for her. Cut them out if they get bad, but gradually she will be happy enough for you to work on them. No matter how badly you want to, don't restrain her when she's had enough and runs off. It's important for her to feel like she has a choice in what's going on.