I would suggest that herbici.de is not, perhaps, an ideal hack because it refers to something that doesn't lend itself at all well to the premise of 'domain hacks'. In other words, I can't see any herbicide manufacturer or vendor wishing to get with the domain because I don't think that herbicide is marketed in the same way as other products might need to be. And as for conceptual uses for the domain, I don't see any opportunities at all there... not even in an ironic way.
Citronel.la, on the other hand, is a better name and it has some options for development.
Good luck!