If you are going consume salvia, I would try every other method first besides smoking. Personally I feel that salvia use is highly introspective, and it's use shouldn't be taken lightly although we white people like to think of it as a recreational drug. it's not a party drug. If I were in your position I would think about buying a plant and growing it. That way you can get as much of it as you want whenever you want, and you will not have to buy the cheaply made extracts, Sagan knows how much shit they had to use to process it.
If you have a lot of leaves you can make a tea by juicing a bunch of fresh leaves. Personally I found that the trips I had from leaves where a lot more understandable and mind blowing, without just fucking up your brain to the point where you can't even understand what's going on. This type of titration is excellent at reducing the stress level during a trip. We like to have control, and it's easier to accept that you have no control when the trips on set happens more slowly over time.
I would consider doing half the dosage at first, wait a minute, and if it doesn't seem to be doing anything take another one of the same amount. Salvia and DMT are completely different, but the fact that you have already tried an entheogen should allow you to process it more easily. In my opinion, all things besides harm to other people (in any form not just murder) should be legal. We should have a system in place where people with mindsets based in logic have access to pharmacological compounds that allow them to expand that logic.
Also, the first time I tried salvia, I had a onie of cannabis to calm my nerves. White people fucking bug out when they try salvia extract, there own thoughts betray them and they can't cope with the stress so they start screaming or do dumb shit. Don't be that guy, take it slow and easy. You never hear about someone doing 10 hits of acid their first time, and then just having a great time. It just doesn't happen. Salvia will take you within yourself, and allow you to experience your own ideas in a world of there own. The whole of the universe is at your fingertips, and you are the driver. Make sure you aren't drunk with power, like most of the western world is.
Sincerely,
ILovePlants
P.S. After trying both extracts and natural dried leaves, I think that something is lost in the extraction process. Just my opinion. Stay safe.