Josh Clark and Chuck Bryant outline various ways to process human corpses. One option on the horizon:
Alkaline hydrolysis is an established technology that is already in use—albeit for the disposal of cattle infected with spongiform disease and cadavers that have outlived their usefulness at teaching and research institutions. Because of the utter lack of sentimentality attached to the process and the resulting goo it produces, alkaline hydrolysis has been largely left untouched for regular old funerals, even in places where it’s a legal means of disposing of corpses.
If the green lobby ever gets true power and starts wielding it against end-of-life norms, you will soon likely have no choice, however, so getting on board with the idea of having your body reduced to an oily, neutral substance sooner rather than later can help you to be a true early adopter in this area. Even more appealing, it uses about five to ten percent of the energy cremation does.
How it works:
In the process of alkaline hydrolysis, your corpse will be slid into a large stainless steel contraption that looks a bit like a freestanding pressure cooker, mainly because that’s what it is. An alkaline solution is introduced into the sealed chamber and heated to between 170 and 350 degrees Fahrenheit (depending on which method is used) and allowed to stew until your skin, organs, tissue and viscera have completely dissolved into the solution. A similar process also introduces pressure to the mix to speed up the process.
All that’s left over is a squishy version of your bones, which are then crushed and presented to your family. The rest of you is gone in virtually every sense of the word: The alkaline solution and heat completely destroy DNA; even a transhumanist would have a hard time conceiving of you being present in the solution at the end of the four hours.
Update from a reader:
As others will certainly point out, the technique described in your post was documented in the Mary Roach book, Stiff: The Curious Lives of Human Cadavers. Highly recommended.