Hi. I know one must wash after scratching scalp. Is this just before prayer. If one scratches behind neck/ear and cannot wash before buying food,is that ok?
While it is preferred to wash them right after scratching your scalp, you don’t have to. You only have to have to have washed them before you make a bracha daven etc. By the way you only have to wash them once and even if it is not with a cup, (although according to some opinions it is better that way).
As a side point yoו do not have to wash your hands when scratching behind your ears or your neck, but only if you touch a place on your body that is usually covered.
O:CH 4-18, M:B 4-39