Correct me !

Hello SuSE folk, Correct me, before I do it, if I'm wrong. After building a rpm or doing a rebuild of an src.rpm the files in /usr/src/ are useless correct? The builds, specs, etc.? Got a lot of stuff in those files which seem to be all intermingled from previous operations and is getting confusing. Can I just go in and clean them all out?? If you say yes, I may have another question in a day or so. Bob S.