i've bought and tried it myself, and i do like it.. for climbing routes.. indoors.
that is when i notice my hands sweat less, i chalk up way less than without liquid chalk.
with bouldering though, it works until i slip of a few holds, then i'm back to chalking up.
i guess with routes i hardly slip of holds so the top skin layer stays intact, where as with bouldering the top skin layer, or at least the interaction between the it and the super-liquid-chalk-resin wears off