Disinfectant that will benefit you orally (5-3)
I believe the answer is:
sheep-dip
'disinfectant' is the definition.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for sheep-dip that I've seen before include "Fleece disinfectant" , "Farm animal disinfectant" , "'Pesticide mixture for ovines (5,3)'" , "Farm animal's bath" , "Pesticide bath for proverbially silly animals" .)