They are called dematting combs. I wouldn't recommend them as they are sharp and cat skin is thin. Sedation and clippers is what I recommend as an ex groomer. Best done at the vets office.
Thank you also.
The Vet has done it for me in the past when Chimee has been there for her check ups and vaccination as she does not wriggle at the Vet's. However, she is understandably not a fan of the Vet and as I do not have a car at the moment, would have to travel to the Vet in her crate on my garden trolley
The knots are not tight to the skin .. would the dematting tool be OK if I can come from under the knot?