Advice from a plumber... DON'T PUT THAT STUFF DOWN THE DISPOSAL!!!
Unless, of course, you WANT to pay the overtime rates!
Once the grains pass through the disposal, it is essentially paste. If it doesn't clog the drain right away, it deposits a nice layer of the stuff inside the pipes. Compare it to a clogging artery, eventually you'll have a heart attack. In this case, the heart attack is a backup, and the actual heart attack comes when I give you my bill for snaking your drain.