yeah I have always used isopropal to clean heads and in back in the olden days when you had to fix upc code scanners instead of swap them we had to use 91% isopropal to clean the mirrors and holograpic discs cuz 70% from the drugstore would leave a haze that degraded performance
I always used 91% isoprpal on brakes cuz thats what I had kicking around from work
