do i have to wash the base or use shampoo at all? because i think it will be a lot easier to know exactly where the unit needs to sit if i have it styled already. like is it fine if i just take off the tape and residue from the base and my head and then just reapply? or will there be scalp oils etc on the base that needs to be washed off with shampoo? i was thinking i can lightly clean the base so that the hair barely gets wet. anyone have any tips for this?