Electric play is advanced play. It's also important to locate good sources of information and good teachers, and to check their information. Dragon has been a paramedic. I checked his information with a Seattle electro-enthusiast who is a nurse and who attended the workshop, and with an electronics technician who attended the workshop. Dragon spent some time describing the function of the heart, which is regulated by an electrical impulse which can be interrupted by electric play.
Some devices conduct electricity on the skin's surface.
Paddle bug zappers are currently popular. The violet wand falls in this category too. Some devices conduct electricity into the body. These should only be used below the waist. And electricity should never be allowed to arc from nipple to nipple in the area of the heart.