It would be a bit more perverse 'fun,' though ... to have a human gauntlet for him to hobble down ... with every person extending to the traitor their extreme displeasure over his treasons and arrogance. Even if merely verbal curses ... I don't think he'd enjoy it--say a thousand people on each side ... A good many might even suddenly need somewhere to project their excess saliva.
Or maybe he could be put naked in stocks at the main entrance to GOLDWATERS in Phoenix on their busiest afternoon?
I should stop. Not the most redemptive use of creative thinking. LOL.
Seek audience with the High Sparrow. Perhaps he can arrange a walk of atonement for Governor Moonbeam.