DON'T use bleach! Unless you know for SURE it is a home test. If they send it to the lab it will fail the pH test and you will fail the test.

The best advice I can give you is to keep your metabolism up, and smoke on fridays after school. Then you got 2 whole days to get it out, drink lots of water too.

It would help if you could find out what time they tested. That way you could just not smoke for a week or two before the testing.