Killing lots of cells at once is a recipe for trouble. Your body's clean up mechanisms are overwhelmed and you die, basically.

This is true, but you can control this by controlling the dose or using locally.

Well, sure, that's why people who use decouplers scare me.

Yes this is what I thought too. I have no idea why it never was developed for humans - the original idea was to use it to make lean meat. Done with monoclonals and careful dose escalation it would be a huge hit.