We have long done this with our dog Bacci, only we have an attendant--not the person brushing--do little fingrtips full of pb at intervals. Downside it requires the time of an additional person. Upside, you get pre-pb anticipationg, actual pb time licking and getting every morsel from the finger of the attendant, patient attention and anticipating of the next batch, etc. So that one little finger-tip full of pb can get a good 1/4 of the dog brushed. We have a big dog, 100 lbs of love, so we have a lot of brushing to do. A fine idea which I can vouch for.
Thanks for posting.