I think to be fair - and we have to be sometimes I suppose......- I think one round of the marbles would be enough for him. But I think there needs to be a catch in the challenge. I wondered if every time a marble hits the metal tray the electro ramps up a bit until say two thirds of the way through it's at 100% for the rest of marbles. This would give him some incentive not to allow them to fall and he would prolong his position by himself for as long as he could. Another thing occurred to me - how about making the tray so that only one marble can be released at a time and he actually has to jiggle his body to get them off him, thus getting ass shocks to release them, then use the same method as above. No release till they've all dropped.