Gary,

My vet recommended using the Dermabenss shampoo because my pit use to have itchy sensitive skin. What I do is follow the directions on the label.

Wet my dog down. Get between the toes and on the pads etcetera. Leave the shampoo on for 10 mins. (I take my dog for a short walk on a leash during this time.)  Then I wash him off and dry him down. The shampoo is gentle enough to do this once a week for a month until the infection is better or cured. Then wash once a month thereafter. 

It's smart to sanitize where he normally sleeps as well and clean blankets he lays on before washing him.