I was taught by my brother long ago how to heat and rub charas to fluff it up before smoking. The methods he taught me work great for a decent size chunk but not so well for little peices of bubble hash. Rather than heat individual peices or put a bunch in a test tube and risk them sticking at the botto I've switched to a diffrent method. I put a layer of the small hash rocks on the lid of a mason jar, then place the lid on a jar. Then I place a halogen desk lamp within a few inches of the hash on the lid. I wait a few min while keeping an eye on it. If left too long it will smoke and go hard. If you leave it just long enough it will turn to a fine powder with almost no pressure. Makes for some lush hash rips!!! It's also great for powdering a bunch for lacing a joint.