Either one but why wash only the area? I love Sustain Alpha. One of my favorites. Used it dating back to primordial performance days and fell in love. Anyways, I apply it after my morning shower once I am completely dry. I use a wide spread technique to cover a lot of area so I don't see what the point/purpose would be to only wash the areas you apply it to. I mean, if you are in a bind then sure.