Well, I finally tackled the job. I removed the tray from the flex drawer and just looked at the messy caramel mess and considered different ways of cleaning it out. Finally, I decided to pour a little Goo-Gone onto it and I let it sit for 10 minutes. After that, I poured enough cold (not HOT) water to cover the stain, and let it sit 5 more minutes. Using cold water is important: if you use hot water, it will just continue to 'cook' the caramel. Use cold water only. When I went back to check it out, I found that much of the sugar had dissolved in the cold water. It was a breeze cleaning it out -- I just scraped out most of it with my finger and then wiped the rest of it clean.
Of course, I did end up spilling about a quart of water on the floor because I forgot that there were air holes on the bottom of the tray. Other than that, it was a success!
This method will also work for your bowls and pans that may be affected by burnt and/or hardened caramel! Good luck!