Use an ice-cube maker thingy... that way each lump is pre-measured and then you'll be set. The temperature thing shouldnt be a prob, it has a boiling point of arounf 280 Degrees C.
Maxi
btw: the best combo ive used so far to mx with GHB (salty taste) would have to be blue powerade (or anyone for that matter) coz it already has that salty-ish taste, or STRAIGHT cordial, about a shots worth.