Thank you for your question. Palo Azul is a tea and works by making you urinate more than normal. The idea is that if you drink enough water and tea, then it will cause you to "cleanse" your system.
Whether or not it works depends on which drug methods are used by the testing lab. If they are testing metabolites of the drug, it will not work for a sensitive process.
You need to use it at least 48 hours in order for it to work,and even then there is no guarantee.
Many people make the claim that it has worked for them. BUT, research evidence suggests that this is not universally true.
It is not a masking agent.