[cerulean]

For the airlines, I have heard this recommendation:
to get a few pieces of nylon cable tie (for electrical cables, sometimes called nytie or ziptie.... available at hardware stores) and zip it through the kennel and wire grate. (you might have to drill a small hole in the kennel).
They do make a very heavy duty one, about a quarter-inch wide. We use it for securing anchors in stormy weather, I think it could withstand the dog's chewing.
As an added bonus, no one could let the dog out without you knowing, because the only way to get the cable off is to cut it with wire cutters. Tough stuff.