I doubt it's too accurate. The states with the most dry counties should have the lowest alcohol consumption rate.
Isn't that a bit like arguing that the states with the strictest abstinence-only sex ed should have the lowest teen pregnancy rates?
No. The high teen pregnancy rates in the South are because of lack of contraception, not higher sexual activity. The states with a high rate of dry counties may have the highest occurence of moonshining, bathtub gin, etc. ...but certainly not the highest rate of drinking.