Response from friend: "I just put Jack's ashes in a clear glass bottle with a stopper, and put it in my checked bag. There were no questions or problems, on the airlines or the Princess cruise ships. I spread ashes on at least two separate cruises, to the Panama Canal and to the Baltic, and it was fine.

After all, you can carry a pistol in checked baggage, as long as you have the pistol and the ammo separately, and it isn't loaded.

So I don't think you'll have any problems. But if you are concerned, you might use an opaque container with an innocuous label, as you suggested."

I'm leaning between the blue plastic bottle or a prescription bottle- definitely in my carry-on so some bozo inspecting my luggage doesn't think it's cocaine and steal it. I'll keep a death certificate with me. I like the idea of pointing it out and telling the TSA what it is before they X-ray the bag- I suspect once I tell them it's DH's ashes, 99% of them won't want to touch it.