No don't know anything about them, but there are several of those like them out there. I did notice one of the buildings in there Before/After Pics was the Frank Erwin University of Texas Center. I was there a couple months ago and took this picture cause I thought WOW this thing need cleaning bad. I wonder how long ago it was cleaned. I took these pics a couple months ago when I was at my nephews graduation at Univ of Tex. One is of the same building and the other is of a return air vent that was just about fully blocked w dust.
It seems they are doing building cleaning on brick, limestone,ect... Using no pressure. I understand soft wash, but I have also delt with severe black stains that a 50/50 roof mix would not phase. Had to use pressure.