Don't roll salvia in a blunt, I've made that mistake. Just gives you a kind of weird high. Like mentioned before smoke it out of some sort of water piece and hold it in as long as possible.
I've done it 2 or 3 times and each time it was equally as crazy. I've seen a 5 foot bottle of mustard talk to me, a block of cheese about the size of a 2 cube box, and laughed hysterically for 5-10 mins. I've heard stories about being in "super mario bonus levels" and even sneezing out a tank and seeing an army around you.