I love the game theory of this.

For a charity, you could choose a good cause that upsets assholes. So they have to donate money to the charity to prevent it from getting the money that was donated.

Last donation dictates the charity that gets the money and resets the timer

And the minimum amount must be >= last donation.

Edit: Wait, are we reinventing poker?

What if you donate on behalf of a charity and which ever charity has most donations gets the entire pot?

Sounds closer to reinventing the penny auction (where did all those sites go?)

https://en.wikipedia.org/wiki/Bidding_fee_auction