Heat based male contraceptive:

[Cumference]

I was aware, that if the testicles do not descend, they will be too hot, and the sperm production will fail.

But I was not aware, that it actually has been tested as a rather efficient and (somewhat) reversible male contraception.

A simple rubber band or a string (or specially designed undies) to keep the nuts close to the body, and fertility will plummet.

A diy version (rubber band, then string) with results from long term use:
http://www.puzzlepiece.org/bcontrol/malebc.html

And a commercial version:
Site:
https://thoreme.com/thermal-male-contraception.html
Movie of use:
https://drive.google.com/file/d/1cuz8qR6FgMv5Kv8ih6bJqneL5Sbco8po/view

It has also been done surgically and with the magic undies:
Paper: https://www.tandfonline.com/doi/pdf/10.1080/01485010050193931
It also discusses other methods.


I guess I’m a horny nerd. This intrigues me.

 

[pplwatching]

A little bit easier to read : https://www.dontcookyourballs.com/heat-based-contraception-natural-birth-control-for-men/

 

[TarnishedPenny]

There were, if my memory serves, studies done c. the 70s which had men sitting on, in effect, a toilet seat with a much smaller opening. The boys were heated v. briefly with a carefully calculated dose of either microwaves or X-rays. (No, I ain’t making this up!) I gather that it worked but...

The ‘but’ is the biggie.

 

[ShesInsatiable]

Roasted nuts...

Eaaaw!