Actually there is no miracle solution. Personally I use TENS pads on the balls, but they are not sticky enough and not supple enough to take the shape and folow the changes in shape. Ideally we need a thinner material, and as souple as the ball's skin. They also need to be more sticky, so that not to get loose at any moment. Loose contact makes unpleasant sting and possibly burns, I saw that.
What I actually do is get rid of the fabric on the back side (but not as much as to break the carbon conducting wires, which are not stuck but just held in place by the said fabric). Removing the conducting gel also helps. You get a suppler pad. From here, some adhesive plaster helps at roughly placing the pads, followed by a tight wrapping with some medical bandage, so that the pad will not slip or wander. This helps produce the right sensation, and avoid the sting or burn feeling. I never had skin burns like that, but remember this can happen if a TENS pad gets loose and the contact surface gets very small.
The best contact place is in front of each balls, at mid-height, (assuming you are standing) there are two sweet spots here with better sensations and less sting. All other places produce more sting.
WMC rings work too, but unfortunately they do not make contact on the sweet spot. To try, have two on them, and arrange a "plug" which is kept stuck between the two rings, and have a "head" so that it cannot slip out. Beware that like that your two channels are connected in parallel, this can work with a TENS (if you move the two potentiometer about similarly on each site), but for other devices consult the directions for use.
For the return, nothing beats a butt plug, but here too it must be large enough. Some have two minuscule contacts, I suspect they can produce burns inside the rectum, but we do not know because this place is insensitive. The butt plug should be at least 25mm in diameter, better if something like 40. After, it becomes painful to insert and to remove. And likely dangerous, past 60mm.
The best circuit with a TENS seems to be a double circuits (like TENS do), one pad on the sweet spot on each ball, and the two return wires tied to the butt plug in a safe way. Beware that if a wire gets loose it can make contact in the heart region, or with the left hand, which places the heart in the circuit. Always use your right hand, and always unplug the wires when you set or rearrange your pads.
A TENS is cheap and produce good sensations. Try to have the old ones with potentiometers, the digital screen is useless and it makes unpleasant jumps when increasing the current. For info, I removed the 9V battery from mine, and replaced it with an external 12V battery. It did not fried my TENS, but I cannot warranty that this will work with yours. Prepare for the sacrifice, trying is the only way to know. And digital ones are likely more fragile!
I located two settings for the TENS, but this may vary depending on people: 12Hz for a strong "torture" session, and max frequency, which for a TENS is near 150Hz. If there is no parasitic sting and the pads are well placed, you can litterally feel pure pleasure in your balls, without electric sensations. A kind of orgasm without ejaculation, which makes it repeatable perhaps ten times.
Electrodes on the penis tip also works, but only at max frequency.
Have fun!
