Err.....
I slapped a bunch in a pyrex cup. And held a lighter to it till the fumes caught and the flame stayed lit. After several minutes it had all melted and I added more JPW till I had liquid at the 6oz line. I then let it burn off till it hit the 4oz mark, put the flames out, and added the LLA, waited a bit longer, and added the MS.
It works fine for me.
But -DO NOT USE THE WIFE'S BRAND NEW PYREX CUP FOR THIS!- She will not believe that the "dishwasher must have done it", when you can't get the black burn marks off the cup.