Basic carries vegan shower gels, though not all of them are labelled as such. Look out for Lavera brand.
Furthermore, dm (a drugstore/health food store chain) has its own brand of cosmetics and most of them are vegan and very cheap. They also have a good food selection.
I found Café Guttut's website: http://www.guttut.de/
I'd like to go there some time, maybe we could meet up there?