How best to use that Tens Unit sitting on the shelf?

That Tens Unit sitting on the shelf—the electronic box with its pulsating pad kit, yes, that one. A quick look reveals no thread dedicated to “Tens Units” yet..? Wondering if I missed it.. For science’s sake, has anyone else used theirs elsewhere besides your specific injury?, perhaps for back or shoulder pain..? Where should you place the pads best, and what settings work well..? To cut a long story short, After my wife had such a “Wanderful” Christmas, she agreed to zip me into one of my bags with the internal sleeves.. I stuck the pads on both front and back at a very special spot… The crotch zipper in front lets the wires exit, then you can close it up so she controls the unit.. She was a little unsure about handling the controls at first.., but … once she “saw it in my face” she rolled over, set an alarm for a 30-minute nap.. I was relieved when she woke and unzipped me. I switched it off.. then carefully put the Tens Unit away with respect. My wife enjoyed doing something fun for me., Never been so stiff for such a long time. Just 30 min. No orgasms. Highly stimulating / satisfying., Has anyone else given this a shot? If not, you really should.. Cautions or warnings to note? Just curious,, 🤔