Using bleach to alter drug test?

hi, i get drug tested every so often randomly by my parents...they take my to a lab to get tested, not a home test. i heard that if you dip your fingers in bleach then dip the bleached fingers in the urine, the test will come up negative...weed is the drug they are really looking for cuz i like smokin the fine herb :) so i havent been using for a month but i rly want to start up again so i was wondering if this is true, and if not, what are some other ways to p besides diluting...?