Phrase for snipping of scissors between actual cuts that a barber makes

Solution 1:

How about "idling the scissors"? "Idling" is typically used in conjunction with cars or motors for running without a load, so while it is not the professional term, it's pretty idiomatic. If it is supposed to free the scissors from cut hair, "clearing the scissors" would probably work.

I think the actual motivation is that the screw in professional scissors is self-adjusting, so if you cut a number of thick strands in succession, it might become too loose for good cutting. Clattering the scissors "without load" would serve to readjust the tension.

So another word that might match the purpose is "priming" the scissors.