The fact that you empty an element does (imo) not imply that you want to actually destroy the contents. You could have references to the children elsewhere, and want to re-inject them somewhere else.
If you want to actually destroy them, you could use `element.getChildren().destroy()`; Also note that destroy and dispose aren't much different when used on Elements you haven't added events to or stored data on using MooTools' Element storage. What destroy does, is remove any internal references MooTools has to the element, to make the element garbage collectable. The destroy docs are updated by cpojer (++credit) in the docs for the next release. :-)
