Ultimately it's up to you if and how you want to argue the case for Salvia divinorum. But I've been active on the issue for a while now so think maybe I should reflect on what I have seen.
Some of the posts I've read for example on forums are people basically just letting off steam. Some posts end up being quite negative, suggesting for example that Salvia prohibition is inevitable and that nothing can really be done to stop it. While I can sympathise with where some of this is coming from and I understand why people might simply want to rant in this way, I'd also suggest it's not really an effective way of changing very much.
Another of the issues we have is that there are a lot people with slightly different agendas. For example, people who may have tried (or try) Salvia only occasionally, mostly out of curiosity say, but are really more into other things, like cannabis or ecstasy, often can't help but muddle the argument. Banging on about how you think that ALL drugs should be legalised is not a particularly effective strategy I would suggest. It only helps perpetuate the misconception that ALL drugs are the same. Salvia doesn't need this.
A better strategy is to argue for Salvia and for Salvia alone. On its own merits to say how it's been around for a good few years without causing health or public order problems; how it's not addictive or habit forming; it's not toxic; it has long history of traditional usage without issue; and it is an acquired taste - unlikely to become popular with the majority. - That kind of thing.