Not quite sure I understand the question. Here's what I do maybe it'll help.
Wet hair....use a little bit of any shampoo,(it can even be Nizoral) then rinse immediatly. Then use Nizoral and leave in for 5 minutes, then rinse. Finish up with a conditioner.
The quick "pre-wash" will clean the scalp a bit so the active ingredient in Nizoral can be absorbed a little better.
BHD