Sprinkling salvia in blunts
An entire blunt with salvia on it, would be a waste of money for the salvia. You wouldn't get to trip off of it, you might get the onset though from smoking it like that. I beleive we smoked a bit on a joint once and I got a nice feeling, and then at once was sitting on what turned into a fire engine, and ants were storming me :) Sally-D is a good experience.
Sprinkling salvia in blunts
If your saying you want to sprinkle salvia in a blunt that would be a waste. Not only would the only effective hit (if that) you would get from salvia would be the initial sucking while the blunt is being lit but it has to be at a certain temp, so you would have to smoke it out of a bowl or something. Also salvia would hit you immediately and probably only last up to 5 mins (i'm told) so the weed wouldnt even have taken it's full effects on you yet. Just get a blunt, smoke some weed, get high, then smoke salvia out of a bowl if it's the 2 highs combined with the nicotine buzz you want.