Taking the piss of the legal system

This doesn't seem right. A company [offers]http://www.ureasample.com/pass-drug-test/body-detox-thc.shtml “drug-free clean human urine samples and complete substitution kits” to protect privacy or ensure the accuracy of a drug test.¹ I can see that people who have done drugs might want to avoid being caught in breach of either the law or an employment contract. But is this the way to do it?

Thanks Rebecca.