Seems to be working for this fellow.
Personally, myself, it would take focus off of my balance, lugging this on a roof.
But, yet, the tiles seem to be clean, and he looks like he has this down to a (sub ) science.
I have always heard that this application is a no-no. Maybe it is a no-no for asphalt shingles, but is ok for tile...

Just for the record, I am not bashing this company either, just in case any of you folks know of this firm.
Pro's of this application?

Con's of this application?
http://www.youtube.com/watch?v=41dX-Oxbgak&feature=channel