Do not bathe your snake BEFORE a shed. It will make the shed much more difficult for the snake and remove the oils that help the snake naturally shed.
Balls don't need much exercise. They get plenty from eating alone and occasional handling. Many people rarely handle their animals and they do just fine.
Giving a snake a bath will not force a snake into shed.. that doesn't make any sense.
I give my balls a bath when they are having trouble shedding and especially for my KSB.. who seems to get dehydrated during a shed (and won't use his humid hide).