My girl is a semi feral who doesn’t do a great job of grooming herself and also doesn’t allow me to brush her. So a couple times a year when I see her developing mats I capture her and we go into the shower stall. Because it is a small confined space she doesn’t have anywhere to run and I am able to get a Furminator brush through her to take out mats and loose fur. I bring in some wet food or treats to distract her let her focus on food instead of me brushing her.