It’s gray and smells like manure — and it may be worth a lot of money.

Ambergris, which is also known as whale vomit, is a waxy substance secreted by sperm whales and used by some perfumers to make their scents last longer on the skin. Last year, a couple in the U.K. discovered a lump of ambergris that weighed around 3 and a half pounds; the foul-smelling, gray lump was estimated to be worth around $70,000.

Doc shared this unusual method for making some extra cash on today’s show. Listen to the full clip (above) to hear more ideas for (totally legal) side hustles.

To see more from Doc, visit his channel on TheBlaze and listen live to “The Morning Blaze with Doc Thompson” weekdays 6 a.m. – 9 a.m. ET, only on TheBlaze Radio Network.