It's always best to use an empty bong (i.e. no water) with salvia. Also, it's better to hit it as hard as you can and as fast as you can. The first time I broke through with salvia, I used a cheap plastic bong without water, salvia 10x, and a Bic lighter. I put in half of the gram of salvia and ripped it as hard as I could, and I still can't even recall the flame from the lighter touching the bowl. I've read a lot about torch lighters working best for salvia, which may very well be the case if you're not hitting it hard enough, but I've never used a torch lighter with salvia and I've had many devastating salvia trips with salvia 10x, an empty $9.99 plastic bong, and a regular Bic lighter.
On the other hand, I've had friends that've used this same bong with the same salvia that got absolutely no effects which I attribute to not hitting it right. Holding the lighter over the bowl and taking 5 seconds to clear it just isn't going to work most of the time. You want the stuff to burn as fast as possible at the highest temperature possible, while getting all of the smoke in your lungs. Spreading out a quarter, half, or near a gram of salvia over the course of multiple seconds is just going to make you lose your material.
So.. My advice is to not use water in the bong and hit the stuff as quick as you possibly can, THEN worry about holding the smoke in (if you're even able to reason at that point). The times I've broken through on salvia, I was fighting for dear life before I could even taste/feel the smoke that I inhaled. I always just remember flicking the lighter, starting to inhale, and then getting shredded by wheels/turn styles/carnival music/grocery store signs/my childhood.