I only clean them well because the last time I used one it turned out there was a red back in the hollow and it ate my stick insects!
its better to be safe then sorry..... please disinfect them everytime you go to place a new stick in an enclosure as you could be introducing all sorts of stuff mites, bacteria etc....
I've never had mites or any health problems with my snakes, whereas a mate who isn't so top notch with his cleaning has dramas with mites and all that nasty stuff -_-
Chances are you mate got mites from poor quarantine procedures, not from branches