...that gaming regs do not require the destruction of retired chips, or chips from closed casinos, but rather any disposition approved by Gaming....

...it's also true that Gaming no longer approves any disposition other than destruction, so far as I'm aware.

The only exceptions I know of are those situations in which the licensee that issued the chips no longer intend to engage in the gaming business in Nevada. In those cases, they don't much care whether Gaming approves of their disposal methods or not, because they no longer need their gaming licenses. Gaming has jurisdiction only over license holders. If someone's willing to leave the gaming business (one example is Dunes; another is Bourbon Street), destruction likely won't occur because it's expensive!

Michael