When Dave Grohl was asked to create two works of art for a charity auction, he procrastinated so long that he wound up drawing them on the day they were to be exhibited for sale.

The results are done in Sharpie on the back of corrugated signs from the 2023 edition of the annual Sea.Hear.Now festival in Asbury Park, N.J.

One features Grohl’s instructions for making a beer bong while the other shows plans for emptying a cassette tape to smuggle hash inside it.

The auctions close today, with the highest initial bids at $6,501 and $5,100 respectively.

Grohl explained, “We used to make these diagrams for runners backstage at shows: ‘Go to Home Depot and get this sh*t.’ They would literally like get it and screw it together before we played.”

Art for this auction is collected annually from musicians who are playing the festival to showcase and sell to raise money for local charities.