I've drank Habu-sake many more times than I should have, both in mainland Japan and Okinawa. It's pretty strong and horrible, and sells mainly due to the "Oh cool, I'm drinking something with a poisonous snake in it!" factor.

In AZ they had something similar with a rattlesnake in it...a tradition in the SNCO club. You actually got a certificate if you could drink a shot of it and lick the inside of the glass so thoroughly that when set afire the flame inside the glass would burn no more than 10 seconds.