How do you dispose of Liquid Fire Drain Opener?

How to rid yourself of Liquid Fire

The best way to dispose of it would be to pour small amounts down the drain, wait awhile, and then flush it out with some water. Repeat this while waiting in between sessions because the water will cause the drain opener to heat up quite a bit.

If you want to keep the flora in your septic tank alive it would be best to neutralize it. Liquid fire is sulfuric acid. You can first carefully mix it with a base thus creating a salt and water and then flushing down the drain. Common bases you could find around your house are baking soda (sodium bicarbonate) and ammonia water (ammonium hydroxide). The latter will actually flush fertilizer (ammonium sulfate) down your drain :)