igotaratidea

What if you added the ashe as a last step?

A layer of ashe burned in after the piece has been blown.

Spy Game is a pretty good movie too.

They might have gotten the idea from here...

https://en.wikipedia.org/wiki/Karen_Silkwood

Nuclear plant union activist murdered by radiation poisoning planted in her home.

I was thinking the same thing.

If you still want to do something similar you can do ceramic.

Not as cool as glass but you can incorporate the ashes more easily.

That's cool and all, but it also makes this world a lot scarier.