The liver is what detoxifies drugs. You best bet would be to help the liver along. If they can test saliva for the drug it would stand to reason the oil pulling might possibly help a little in removing the drugs, but how much and how fast are the questions. I would think it would be negligible. Helping the liver is what you need to do. You might ask Telman on the Liver Flush Forum what she thinks about a Liver Flush to help liver function.