removing undercoating

hi y'all

i am working on my 67 cuda restification, i plan on removing all the old undercoating from the body but most specifically in the wheel wells, i am going to strip, reprime, and repaint the undercarriage with dupont GM chassis black,

i plan on using a friends pressure pot sandblaster to clean the metal up with low pressure to reduce or prevent the metal from warping prior to repriming and repainting, but what i'm dealing with is chunks of undercoating. i have removed some of the factory stuff by warming it up with a bernsomatic torch, and scraping it with a paint scraper. is there an easier way, or do i just have to put the time in? plus theres a bunch of aftermarket undercoating sprayed in spots under the car. this stuff is uber nasty, and sticky, heating it up and scraping it wont work as heating it just makes it more liquid and sticky.

any ideas on removing this stuff

thanks
matt