You don’t need to live near an active volcano to benefit from lava rocks in your barbecue grill. Lava rocks and their ilk are used in gas grills to diffuse the heat evenly, generally in the same manner as charcoal briquettes, except that you don’t have a massive messy clean-up of charcoal ash after each barbecue.

But lava rocks are not entirely care-free; they need to be kept relatively clean. Because lava rocks are porous, grease and food drippings tend to build up on them. As you’re cooking, a flare-up can burn your food and give you unintended results - as in, “you did say well-well done, didn’t you?” Lava rocks can be cleaned and scrubbed, using soap and lots and lots of water and then lots and lots of time to allow them to dry out. Because lava rocks do eventually disintegrate, at a minimum, they should be replaced at least every other season (more often if you prefer not to clean them at all).

To minimize your clean-up effort, rearrange the lava rocks every once in a while, and after you’ve taken the last food item off the grill, turn the gas up as high as it will go and let the residue burn off the rocks for at least 10 minutes.