I think generally speaking they would just add the charge tampering with evidence. Unless you can destroy it so deeply that they can't look at what is left and determine what it was to start with, which is not very likely. Pirhanna solution? I don't think this is a workable idea.
First of all.. Wasn't there a pretty similar post in the past a lot of people made fun of?
Second: In my opinion this is not the smartest question (or way to do it).