I always assumed everyone used this technique to test 9V batteries. I've done it all my life and figured it was universal. I have always wished they put the terminals of 1.5V batteries on one side instead of two so I could test them, too; although it seems likely the voltage would be too low to feel.

Really this is a big non-issue. It's no more unpleasant that putting putting a dollop of straight lemon juice on your tongue.