It seems there are many ways to clean Invisalign trays. The Invisalign company even sells a cleaning kit, but at $75 for 50 cleanings that seems crazy expensive to me.
What have you found to be the best way to clean your trays?
Also, if you tried anything you would suggest others avoid (ie, did you boil them?!) feel free to list that too. Sometimes knowing what not to do is just as important as knowing what to do!