Surprisingly enough the "Disposal Doctor" on InSinkErator's website was able to help me resolve the problem. With a 1/4" Allen Wrench and my trusty flashlight I gave the Doctor's advice a try. I figured I had nothing to lose -- if this didn't work I could get a new unit from Lowe's tomorrow and install it sometime over the weekend. I crawled under the sink, set up my flashlight and grabbed my pack of Allen wrenches. Sure enough there was a wrench hole and it was indeed set up for a 1/4" Allen wrench. Unsurprisingly, upon my first experimental tug, the wrench did not turn. The Doctor said this might happen and that it was okay to use some force. I applied a bit more elbow-grease to the wrench and suddenly there was movement! I spun the wrench a bit in one direction, then back in the other, gradually working up to full circles. There was a rush of water as what was backed up into the basin was freed to flow and I reset the InSinkErator's built-in breaker, which I had tripped in my frustrated on-off switching action earlier this evening. With some trepidation I hit the wall switch but I was pleased to hear the normal whirring of the disposal and saw a steady flow of water disappearing down the drain. Success, I had a properly-functioning disposal that was back and insinkerating again!
I'm glad this worked out. While I would have enjoyed buying myself a shiny new 3/4 horsepower disposal I was not relishing the idea of spending the better part of a day underneath my sink ripping out old equipment and installing new.
In other news: this Friday afternoon will see the arrival of my parents on a holiday visit from Minnesota. I expect I'll be pretty busy but at some point Curmudgeon will have the chance to meet the people who spawned and raised me. I'll be getting a new couch (where am I going to put yet another piece of furniture?!?!) and some incredibly awesome oak bookshelves that my mother managed to find in the thrift ads. Hooray for bookshelves, I'll finally get my living room floor back from the stacks of manuals and texts that have been sitting there since I moved in!
It's a never-ending circus ride