Try sticking your naptha with crystals which need scraping into the freezer;once its properly cold it gives you more time as the crystal dissolve in anything less than very cold naphtha.When done this way I find the cystals tend to stick to the side of the container so you can pour off much of the naphtha (and stick it back in the freezer in case more crashes out) and begin your scraping.
Vovins tek is excellent as its step-by-step approach allows you to understand the various steps and rationale for each.Newer techs like BLAB forego the acid 'cook' stage with excellent reults so its probably not absolutely necessary to do this step when working with MHRB.
I am paranoid of my brain. It thinks all the time, even when I'm asleep. My thoughts assail me. Murderous lechers they are. Thought is the assassin of thought. Like a man stabbing himself with one hand while the other hand tries to stop the blade. Like an explosion that destroys the detonator. I am paranoid of my brain. It makes me unsettled and ill at ease. Makes me chase my tail, freezes my eyes and shuts me down. Watches me. Eats my head. It destroys me.