I'm posting this for those of you who may have a hard time finding 100 proof vodka for making menthol drops. I seem to be sensitive to even the small amount of water present in lower proofs and gag like crazy. Then I thought, since I usually add a small amount of peppermint to my menthol mixes to cut that "Vics" taste, why not dissolve the menthol crystals in peppermint extract?" I added the crystals slowly over time until I had the taste I was after and ended up with an extremely concentrated menthol flavoring.