I find that the trick with the Zook is to rub it in well until it forms a paste or wax like coating and then buff off the excess. Then I use a microfiber cloth to polish it really well. If you leave any residue on the shield it can distort your vision and seems to create the fogging, not prevent it. Went for a great ride today and had absolutely no fogging...
Slideshow of today's ride
Thanks to my brother for providing the webspce to put up the slides...
TripleThreat