I have a furminator for my lion head angorra cross, but the thing about them is they are incredibly harsh on skin, and rabbits have skin like paper. A lady who owned a pet shop up from me used a furminator on a rabbit and she tore the rabbits skin while grooming.
I think recently on this forum an owner scratched their poor rabbit badly enough with a furminator as well
So while I own one for my rabbits , I don’t advise it and I don’t really use it.
Depending on your rabbits coat type you have a lot of other options. For long coated buns I use a combination of various tooth combs with different spacing- start large, work my way to the fine spaced ones. And I also use a small slicker brush.
For short hair I dont really bother with brushes, I wet my hand and wipe it over their backs (the wet on your hand will get the fur to stick to it, wipe your hand and continue this way -your hand shouldnt be soaking, just damp enough to catch the fur)
or I use a lint roller and roll the fur off that way