Rubbish, anybody with a basic level of engineering could see that thing is about as much use as an ashtray in a pub.
He is holding the pole wrong for a start.
Using the pole as he is in the demo, the "Waspak" is probably serving the purpose of taking some of the weight of the pole directly off the arms.
However using the physics example of a beam and pivot point, in most situations it's possible to hold the pole further up (instead of at the butt cap) so the pivot point changes and the weight is better balanced.
Thus saving the window cleaner looking like a prat.