A physio in Canada treated my rotator cuff tear (bad one, 3 of the 4 had tears) using the Graston Technique in 2005 when I lived there. It hurt like hell. It worked. Would other techniques have worked as well, probably, I’ll never know.
The physio was an ex university wrestler who specialises in treating injured shoulders. He was good. He
used the Graston tools because they could get into the rotator cuff scar tissue more effectively than using fingers. I’ve seen plenty of physios both excellent and mediocre, who don’t use Graston, and one excellent physio who does use it.