I usually aim to melt at around 40-45C, but only a small quantity at a time. Using a plastic knife, slice, chop, and gouge lumps out of the original bottle and place in a small jar. Add an equal volume of water and melt. Repeated melting of the original bottle will (according to the instruction leaflet) will increase the fog levels, as will extended storage in poor conditions.
Originally Posted by EASmithV