I agree, there are much bigger problems in the world than bath time with the grandparent. Being a solo father of a 4 year old daughter, I made the decision to stop taking showers with her at the time when she attempted to point out and grab my "tail." :-) Despite it being easier to wash her hair in the shower, I value the sanctity of a nice, relaxing shower a wee bit more. That being said, when she trots off to visit the family, whether or not the grandparents are taking baths with her is the least of my worries at this age.
My daughter Ivy had a litle section of the house off of the living room just for her sizeable toy collection. Most were well researched before their purchase to ensure she would transform into a well educated and adjusted little person. She is a very happy, very intelligent (completely unbiased opinion, I swear) little 3 year old. And her favorite toys are... the pots and pans in the kitchen drawers. ;-)