Well, first of all, DON'T WORRY!! Fasting is one of the best things you can do for your body!
As for substitutes for chewing, my first Master-Cleanse I spent a lot of time watching Food Network and did a lot of salivating... hehe Also, on this forum there is a group called "Sniffers Anonymous." We admist to sniffing food in place of chewing it. *wink*
Meanwhile, on a more serious note, why not take out that "I want to chew" energy on a nice walk, or taking photos of the sunset, or playing a game with a child. There are so many other important things we can do besides chew ... enjoy its absence while you have it, because the Master-Cleanse won't last forever, and the food will be there when you're done.
I will be joining you soon - I plan to do the Master-Cleanse the month of October. Maybe we can encourage one another then? God bless and fast on!!