Cleaning a Boy with a Cast

So after about 10 days Ian needed to be cleaned. We had been avoiding this task, knowing it wouldn’t be easy. So we decided to go with the old duck tape and trash bag route. He was not a happy camper, he shouted some crazy things.

NO, I am not TRASH!
Help.
Shit.
Get off me.

Those were while just putting the bag on, the during the shower part was even worse. Poor C took a cast to the unmentionables and Ian cried like it was torture. Any one have any ideas on how to make this process easier.