I want to trigger JavaScript garbage collection. Is it possible? Why would I want to, or not want to, do this?
Yes, you can trigger garbage collection by re-loading the page.
You might want to consider using a Factory Pattern to help re-use objects, which will greatly cut down on how many objects are created. Especially, if you are continuously creating objects that are the same.
If you need to read up on Factory Patterns then get yourself this book, "Pro Javascript Design Patterns" by Ross Harmes and Dustin Diaz and published by APress.