Yeah man, he had little rubber thimbles made that he slips on his fingers, and that's literally how he plays. By dropping the pitch, he is lessening the tension of the strings, making it easier to push down. He also played the chords on higher frets, but on fatter strings. This also makes it easier to press down, but it also makes a deeper, more muddied sound especially with overdrive. That's where the sound that spawned all the metal bands came from, from a dude's horrific injury. He was amazing at solos too despite the injury, and many of his fingerings were working around his pain, much like django reinhardt did for jazz (and the single note lead solo) decades before due to his injuries as well.