steam on the shield

What do you do to prevent the steam on the shield. Since I started to use the built in head sock I've got problems

 

This may sound stupid, but i have used this for years and it works. Put a couple drops of dish detergent, [Dawn works good] on the inside of the shield. rub it in real good with a paper towel, then rub it off with a clean paper towel, [no water]. Shield wont fog up all night. Tom.

 

I've used the detergent and also Razzle-dazzle. Both seem to work well. The razzle-dazzle seems to last longer.

http://razzledazzlecleaner.com/home.php