Has anyone tried a de-matting brush like this?

I use this. Works well and doesn’t bother my doodle at all

Safari Dog De-Matting Comb,... https://www.amazon.com/dp/B0002ARR2W?ref=ppx_pop_mob_ap_share

Brush frequently with a slicker brush to prevent matting. Once tangles start focus on those spots and make sure you get all the dirt clumps out. Use a metal comb to help detangle. If it gets worse, you may want to try something like the Safari de-matting comb, but opinions on tools like that are mixed. The next step after that is professional grooming.

If she won't tolerate that much brushing, then I'd go with shorter fur on her ears. We keep our ECS's ear fur about even with his ear on the outside and usually shave the inside. Far less matting and easier ear cleaning.