SWIM has tried it, he says 2mg vaporised is already a lot but that what he likes to smoke. Pretty scary though for most people.

The acetone method is pretty good for safely measuring doses;

1) Dissolve 10mg salvinorin per 1 ml acetone and store in the freezer.

2) Whenever in mood get 200 microliters of the stock, evap it to get 2mg of salvinorin