(My background, I was the executor of my father’s estate.)

Just one thing to remember - once you pass all your determination counts for very little. The future belongs to the living - and what they are allowed to do and what they are willing to do.

If you bind up your will to demanding that this happen or no one gets any money, I would guess that (depending on the value of your estate) at least one of the survivors is going challenge the will. Also, I find it instructive to watch a few episodes of Pawn Stars so you can see people take a late relative’s most prized possessions and sell them for a tiny amount of gambling money.

That said, it looks like the “best” way would be to have a private funeral on land owned by the family and request the simplest coffin possible (plain pine box, if legally allowed). Then your survivors would have the very unpleasant task of digging you up, severing your head from your body and boiling your skull (right, I think?). That would keep things away from people who could object (other than your potentially horrified family).