Depends if they roll in something or not.
Really, they all get bathed once every 4-6 weeks. And by bathe, I mean wash, trim nails, clean ears, and blow dry with a force dryer.
Cooper gets groomed every 6-8 weeks. I try to groom Chloe every 8-12 weeks, and since I'm no longer living at home, that is when she gets bathed, too.
For shampoo, Gracie gets some kind of Keto-Chlor based shampoo for her allergies. Cooper gets bathed in whatever, but if it's at home I have a hypoallergenic oatmeal shampoo by Oster, I think. Cynder gets bathed in Allergroom, because I don't want to risk her coat turning into the nightmare it was when I first started dating Mike. Took about 5 months of regular Keratolux baths plus a diet change to get her to where she is now, and I don't want to backslide!