If the spread of communicable diseases is why licensing is required in all 50 states to barber, wouldn't the problem be better solved with legislation focusing in on just the problem, itself?
It can take 1500 hours in barbering school before you qualify to sit for the state exams. How much of that is training in how to avoid communicable diseases? And, do you need that much training to avoid communicable diseases? If the solution is as simple as disinfecting the cutters after each use, isn't it much more practical just to have a law require just that: Clean the cutters after each use.
And, you could have a law requiring the sale of barbers' cutters to be accompanied by the sale of blade disinfectants. In order to buy the clippers, you would also need to buy a disinfectant kit. Plus, you could require a sheet of paper accompany each sale, explaining the dangers of lice and such being spread through unwise barbering practices.
With all 50 states requiring licensing (I do not know how many require barbering school), Utah could become the first and only state to address this problem the reasonable way: Laws requiring the clippers to be cleaned instead of putting people through 1500 hours of barbering school that have little to do with communicable diseases.