I think that if your groomer is planning to muzzle Piper, then that needs some planning!

Muzzles need to be introduced carefully and the dog rewarded for wearing them, (in much the same way as you've got Piper used to having her ears brushed). Otherwise all that is going to happen is that Piper will associate the muzzle with something scary and she may well start to object to having the muzzle on. This in turn could be a real issue if you ever really need to muzzle her, for example if a vet wanted to check her ears......
I agree with you that it would be far better for Piper to learn that being groomed is a good thing. I clip most of ours at home and sometimes go to our groomers for a 'tidy up' - luckily our groomer is a good friend and I stay with them. I would be horrified if she or anyone else muzzled one of my dogs without my permission.
Well done by the way for taking Piper on and being so patient to work through her fears.
