He released a video that starts with BROTHERS OSBORNE and LANCO getting out of their cars and walking into the woods where they see a "shaman." Yes, it's Dierks. He's shirtless and wearing dreadlocks, along with other shaman-like attire.
He leads them through a "spiritual ceremony" that includes burning a stick person, pouring liquid into a cauldron, spitting in the cauldron, and chanting. They drink some of the potion and it makes the Lanco dudes VOMIT.