This is an advanced technique on the cupping theory where the skin is encouraged to bleed prior to cupping being applied. This is particularly effective for areas of the body with very poor feeling and blood circulation.
Wet Cupping should leave a round bruise the size of the cup on the skin after treatment along with a minor abrasion of skin. This is normal and is a sign that blood flow has entered into the treated area which will reduce inflammation and help with the healing process