Ball slapping for extra energy and blood flow?

Guys,

I saw a video online a few months ago about a technique where you gently slap your balls, which gives you lots of (sexual) energy.
It seems to be an old East Asian technique to enhance testosterone and works like this:

With your pants on you take a wide stand, a little wider than shoulders. place hand next to each other on the balls and slap gently with left and right hand alternating.
About the same strength as when you are applauding. Do this a few minutes and your balls and penis feel completely energized. Also I noticed the blood flow afterwards has improved drastically.

Anybody know it? Can't find a lot on the internet, if you search ball slapping than you mostly get BDSM websites.

My balls slap alot by them selves when i have sex. Usually when im balls deeeeeep into a phat vagina and/or doggy style from the back they slap her thick ass or fat vagina lips . . . ......

Yes, I wrote about this in a book about Dallas energy techniques, and it feels good. I try to remember to do it whenever I’m alone. I think it might be a little correlated to better and more frequent, spontaneous directions, at least for me.

True, one should experiment with it and see what works best. But really an improvement for overall sexual energy IMO.