salvia isn't illegal, it would be like them testing you for whip its.. there is no law saying you can't inhale the gas or smoke salvia.. so there is no punishment... not to say either of them are good things to do, but you can get both on ebay, freely, so if someone is testing you for it.. who cares..
now if your going for a standard piss test and you worried about some salvia and your piss comming up hott.. nothing to worrie about... the 5 panal tests are like Crystal Meth, Cocane, Harrowin, Marijuana, and some kinda other narcotics.. type pills, salvia dosn't make the list... never the less i would not smoke a bunch right before taking a test.. but i would imagine its like mushroms or lsd.. just don't show up