I'm going to have to disagree about the shrooms and the marijuana. The weed would be okay, weed does not lose potency very easily, it takes a lot of time and adverse conditions. The shrooms will not lose potency if they are not exposed to oxygen. The question is, is wax airtight? If so, totally incasing shrooms in wax, and making sure as you do so that no air is trapped inside, could preserve their potency for several years.
As for acid, you definately do not want to do this. It shouldn't be to hard to conceal a few hits of acid. If it's paper, stick it in a book or something. If it's liquid, drop it on some gum and wrap it back up, be sure to keep it cool. If you have a vial, don't sweat it. It has been my experience (on several occasions) that cops won't look twice at a vial of acid. Hell, I had a friend get his vial back from the cops after a night in jail.