You can use Rain-ex Product that you rub on your windshield to force water and ice off is great for preventing fogging. One of the bonuses to using this on both sides of your visor is that the water will disperse off the face when raining giving you better visibility.
I know what you're saying, zx6r. I've done it before but only up to a certain temperature. I ride even when it's in the 30's and tears come down my eyes when I crack open the visor because the cold wind's too much. I ride all year round as long as there's no snow or ice on the road. This is the reason why I got the pinlock shield. It's perfect for me. I remember I went out one time at 5 am and the temp was 26*. At that temp, I got to keep it closed.
I heard you could use shaving cream on your shield to stop fogging.
I tried it the other day and it did help. just rub it on the inside of your shield and wipe it off. Dont know how long it will last but I did see a difference.
I used to spit on my visor to prevent it from fogging but it only works temporarily, same with the shampoo and dish washing liquid. I just tried this WeePro anti-fog visor insert, and so far it works perfectly fine. It never fog at all even if you directly breath on it.