I have known about this method for a very long time, but I had reservations. The wet heat method has (some) human testing, and seems clearly non-permanent, or very nearly so. Certainly enough to assuage the reservations of someone who is "pretty sure" they want a vasectomy, but slightly concerned you might change your mind in 10 years.
Papaya seeds. This method couldn't be easier. just as easy as taking a pill. It is important to note that it takes around 90 days to reach sterility with this method, which to me makes me a bit more comfortable considering if it is reversible or not. It's obviously not THAT potent if it takes such a long time to take effect.
Literally all you do is eat one teaspoon of papaya seeds daily. I just buy a bunch of papayas, scoop the seeds, put them in the freezer, and toss a teaspoon in the blender with my protein shake every day. You can also buy papaya seed powder online, but it's crazy expensive.
This method has been tested in rats, but for one year only. They regained full fertility after discontinuing. It also has a long history of aboriginal use, but also we have no long term data there. Anyway at this point in my life, I finally decided I don't give a damn. How bad could the side-effects possibly be, compared to all the pharamaceutical crap people are taking every day. And in the end, to me it's worth it for time management compared to the wet heat method I've been using previously.
So I'm going on about 8 years now, between the wet heat method and this method, I've blown hundreds of times inside many women, zero pregnancies. If for some reason 10 years from now I change my mind, want to have a kid, and discover unexpectedly that quitting them doesn't put me back again after all, I'll adopt. Honestly I think it's unethical as fuck making new children anyway.