sample clearing (Drums)

i u sample some drums do u have to clear it or is it not a problem

Sometimes samples like drum sounds can be recognizable, but personally I wouldn't bother to clear them. I would be more concern about melodic stuff or parts of songs that I want to use which are easy to notice.
That's why I always change it, to suite my needs and to make it more like my own sound. Effects, eq'ing etc.

if you chopped up each hit then you good, but if its a noticeable drum loop then at some point and time you may have to clear. why not try to reproduce the patterns?