I have heard about rabbit owners using a "bunny burrito" as part of their rabbit grooming process.
What is it?
How and when should it be used?
Bunny burrito should really be called bunny enchilada; it's when you wrap up the bunny up tightly in a towel so that only its face and tail stick out, thereby restricting it's ability to use it's legs.
It's most commonly used when force feeding medicine and inspecting oral hygiene and genitals.
Bunny burrito usually is not used for grooming, but could be effective if one needed to focus grooming on an area near the tail or face, however, putting a bunny on a low traction waist-high table, or holding it against your chest, or just petting it with all "4 on the floor" are all preferred of this more stressful technique. Contrary to the information in this answer, it is not possible to use bunny burrito for belly grooming as exposing the belly would also leave the bunny's legs mobile.
Bunny burrito could potentially be used for nail trimming by loosening one edge of the towel just enough so that a paw my be removed and individual addressed. However, the bunny trance method, while considered equally stressful, provides faster quicker access to the rabbits paws and thus is preferred by rabbit care professionals. Moreover, professionals recommend owners try the table method first as it's least stressful for the rabbit.