I was just going to suggest something like that. Just go ahead and count out [number of rebuys allowed] per person playing in the tournament before you begin. Set them well aside from the game so you will know if someone decides to snag a stack and add to their chips illegitimately. Hell, make a sheet with tick marks of some type that shows how many stacks are left or how many have been taken, and keep that sheet on your person so you can always check back and make sure none are missing.