Hashes of dead people sound like you took a SHA hash of each of them to remember the unique mark that they left on Earth forever.
"Here lies John Doe, commit ID: 1b372d0e."
On a more serious note, if the funeral director and crematory did their jobs properly, anything dangerous (such as dental fillings containing mercury) should have been removed, either before cremation or before grinding.
My country is slightly more lenient. My grandparents' ashes are buried in my parents' back yard, and we had to do quite a bit of paperwork to make it legal. It's still illegal to scatter the ashes in any public land or body of water, and I can understand that because certain scenic locations would quickly become a big pile of ashes if it were allowed.