Some artists are already using that residual material to make personal jewelry for the bereaved.
Down here there are artists who put the ashes in glass and there is a service that mixes them in concrete to make wiffleball-looking artificial reef structures
You can incorporate ashes into a glass sculpture
https://www.cremationsolutions.com/cremation-keepsakes/cremation-glass-keepsakes-and-urns
Turn Grandma into a paperweight.
I’m reminded of the ancient Egyptian undertakers putting several animals into a single animal mummy.
For $5,000, the Neptune Society will mix one's ashes with concrete, and put that "sculpture" in a "garden" below 30 feet of Atlantic Ocean. The "sculpture" designs aren't particularly inspiring.
There haven't been too many taking the Neptune Society's "Neptune" offer, so they'll just take over with a usual cremation from the moment of one's death. (That is, if they're made aware of it). No refunds, I guess...
Dad sprinkled mon over her roses.