This dude puts a vibrating egg up his butt and gets off hands free in about 40 seconds. Vibrating eggs are like fat vibrating bullets, are inexpensive, and work really well and are available everywhere online and in all sex shops. There are so many to choose from: battery, USB, rechargable, remote control. You can get single eggs and also dual ones. Some duals allow each egg to be controlled separately.
One tip: pulling on the wires to remove it can weaken or break the wires and even break the wires off, leaving the bullett up inside you. This can leave the bullett difficult to remove. An easy solution is to place the bullett in a condom before insertion. Then just pull on the condom to get it out.