Not if the testing lab is doing their job right.the record of drug use would still be in your hair root if I read the drug information about testing right. So you would be busted.
Get a number #2 buzz cut first...then let them sample the shorter length hair,if you've been clean for 6 weeks you should be aok.
If that long ago, it has passed long ago. Hair is dead cells, and only the folicles are living but only to discard current dead cells, not those from over a month ago