I make shot glasses like a small whisky barrel. They are White Oak, and charred inside with fire. No other finish is used on the inside. The outside is sealed with a mixture of natural pine rosen and linseed oil.
Yes, you can drink out of them, I do! Although every one is slightly different, a barrel generally holds about 1-1/2 shots (a bit more than 2 fl oz).
Use your Shot Barrel for plain spirits (whisky, rum, tequila, etc). Other drinks will get into the pores of the wood and can spoil.
After some use, you may notice a few drips out the bottom – this is normal and unavoidable with wood. You just need to drink faster!
Clean by simply rinsing with warm water. Do not use soap, as it will soak into the wood and spoil your next drink.
I recently did a collaboration with a local artist family, Annie and Rolf Reiser of Botangle.net. They did a wonderful job of laser-engraving names on a set of Shot Barrels. This was a special request by my son to make gifts for his groomsmen. I think they turned out great.