Similarly seppuku / harikiri is a two player game. You need a Second who can lop your head off once you've disembowelled yourself. And that means someone who will either An Hero alongside you in a different way, or who can make sure they don't leave any forensic trace of themselves behind, or take any such traces away from the scene, and arrive/leave without being observed and tracked, else they will be in a whole pile of shit very quickly.

Also come up with an entirely ridiculous yet believable reason for it other than "this gets me hard".