Pretty much... though your 'destroy' method may not actually unset the variable itself. I'd suggest also setting editor=null; in there just to be sure. You could also call "delete editor;" -- either or, I prefer treating it as a pointer, YMMV. Sucks that javascript doesn't have proper destructors... but like most C syntax legacy languages objects just kinda seem shoe-horned in there any-old way.
I also prefer editor = null; You know the object is "nothing" and you don't worry about whether the syntax is working against a variable or property.