This was my first thought, too.
I had a funny idea: allow the player to set the roll delay to anything they like. Then they can set it to "24 hours" for a self-enforced break from the site. It would effectively tie up their account, preventing them from losing their funds. "Sorry, you still have a roll in progress - 23 hours until it completes". For those people who just can't help themselves, but are capable of moments of strength...
That's actually a pretty great idea, however I feel like anyone who would consider using this would probably just put in a new address and play again. If anyone wants me to force a break from the site I could do so manually in that sort of situation.