You could put a resistance in to reduce the juice. Put a 10 Megohm resistor in series with one probe, touch probes, you won't feel anything, then try 1 megohm, 100KOhm, 10KOhm, 1KOhm, 100Ohm, 10Ohm
Somewhere you'll feel the tiniest tingle. At that point stop going by powers of ten and try small decreases until you find the right setting.
This assumes you can get to the electronics to permanently assemble it.
I bought one of the remote controlled dog collar shockers, and they are really painful, even in the lowest strength setting of 1. I did not dare to try a stronger setting, and it goes in 2-digit range!
I found the collar fits just a around the upper tights, and on the leg the shock is 'just right'. Conveniently there were two collars in the set, one for each leg. It is still painful enough to have a good disciplinary effect. It conditions you really well to obey and avoid the punishment. The collar also has a no-shock vibration only setting, which adds to the thrill.
I just couldn't convince my wife yet to use it on me, she is more scared than me. So it remains a thought game for now.
Recently there are a lot of cheap electric shock 'massage' devices on the market, which are less extreme. Some have even remotes. But that is for another post.
One of the reasons why me and my wife stopped all bondage activities. She's not into anything what might induce discomfort or pain to anybody (including herself), and I can't do that to anybody (except myself, to some extent) either.
