The Amish do not use electricity but the Mennonites are more likely to for convenience. So the Mennonite community would be more likely to bathe daily than the Amish. However, I would believe it might be more like 2-3 times a week than once a week. They bathe as they feel the need to. No, it is not easy work but they are used to hard work. As another person stated, they are clean people so I am sure, even if they don't take a bath, they wipe themselves down to clean up on a regular basis.
Cleanliness is next to Godliness.