Mares can be just as bad, I clean between all my girls' teets every few weeks. It gets smegma build up too. Most of the time they really like it but once in awhile they get a little annoyed.
On the sedative free teeth floating I had a fellow do it once by grabbing hold of the tongue and holding it out of the mouth while he floated the teeth, the horse didn't move.
"Until one has loved an animal, part of one's soul remains unawakened..."
- Anatole France