Start scraping, stirring and folding it before it is completely purged. Wax is just oil with air whipped in. If you do it before the alc is purged, you are trapping pockets of solvent and it will never purge right.
I have heard that spme strains do it regardless of method but I think environmental factors (temps/humidity) play a role as well.
Sour Kush turned into a nearly white crumble the first time I made it and a pull and snap the second time. I let it purge longer the second time before scraping.
I suppose you could gently heat what you have in a small dish over a flame. When it starts to soften, start stirring it. Keep heating it and stirring it until you are whipping it like cream. You'll see the texture change. It will become cloudy (tiny air bubbles). When you get it where you want it stop and let it cool.
Hard, translucent shatter or near shatter is the best. The most pure, flavorful, mmmmm. Sour Kush makes ridiculous BHO btw.