I've had ferrets for 20 years, (obviously not the same ferrets the whole time.) You absolutely should NOT bathe them daily. Bathing strips oil the oils out of their fur, and causes their sebaceous glands to go into overdrive, making them even more smelly. For issues with smelly ferrets, you have to clean the bedding regularly. On a weekly basis I would wash their blankies and all of their beds and stuffies. As they loaf around in their beds, the oil from their skin rubbs off on their bedding and accumulates which creates some stink. Another way to reduce odor is to clean the litter boxes 2-3 times a day, and promptly clean up accidents. These are high maintenance pets, but as long ask they have had the musk glands removed, they aren't as stinky as they have been made out to be.