For a variation on 'oral' ingestion Salvia is available in the form of a tincture. This is an extract made from Salvia leaf. It's liquid, containing alcohol. It's basically a concentrated solution taken sublingually. A small amount is held in the mouth. - The salvinorin is absorbed in the same way as the quid method, but (obviously) without the necessity of chewing leaf.
I have tried this form of Salvia. The effects are broadly similar to the effects from chewing. The high alcohol content does not interfere with the experience since it does not require a large amount (and there is no need to swallow it). Even so, the alcohol proof is so strong that it will burn the skin tissue in the mouth if not first diluted with water.
Available only via the States ( - at the time of writing. I got mine through Daniel Siebert's Sage Wisdom Shop>, late 2002). It's easy enough to purchase if you have a credit card. There are no import problems. I got mine within a week.
However, it does work out to be a very expensive method of ingestion (costing about £5-£10 to for a single experience). And personally I found even the diluted solution quite an ordeal to keep held in the mouth, so it's 'convenience', as opposed to simply chewing the leaf, is debatable.