Your standard dripstone cauldron farm.. but no wait time. Sponges will dry instantly when water touches the sponge in a dry climate. [Savanah, Desert, Badlands] Every time the sponge dries..the cauldron will fill, creating an instant lava farm. A dispenser with a water bucket on one side of the couldron and the sponge on the other side. You can fill shulkers of lava buckets in no time. Hands down my favorite fuel farm.