which is faster and/or easier to remove the tar (gack) that was under my carpet?

i'm just looking for opinions from those who've used either method...

thanks.

 

not me personally, but rpi racing rented a huge tank of liguid nitrogen, then shot that crap with it, then hit it with a hammer. it sounds like dry ice would work bu it may be harder to get it in contact with those hard to reach areas. it may be easier to get something you could sray.