Jazzy is really good in the bath, once I get her in the tub. THAT is the tricky part with her. She sees me walk toward the bathroom with "the stuff" {shampoo, towel, treats [she gets a teeny treat for each stage of the bath – in the tub; wet down; soap up; rinse off; out of the tub}} and she takes off to hide somewhere.
Keoki has only had one bath, and that was a day after I brought him home cuz he smelled a little...uriney... after peeing all over in his kennel that first night. He did okay but tried to jump out of the tub on several occasions. I think he'll do fine.
I usually wash Jazzy when she looks "less than clean" to me. I know it's really subjective, but her whites aren't their whitest, and her red seems more brown to me. More baths in summer than in winter -- she doesn't get really dirty curling up by the pellet stove. And every bath is followed by the B-500 -- summer is nicer because then it takes place outside.
I also bathe her when out of town visitors are coming. I like them to meet/see her at her most beautiful!
Gypsy, my golden mix, also has always done a crazy run after her baths through the years, so it must just be a way of A}drying off and B} celebrating release from the torture chamber that doubles as a bath tub.