A neighbor decided to dispose of his dead dog via open air cremation. Instead of doing his research, he used an accelerant and burned up most of his back yard and melted the siding off his garage. The pup's corpse was fairly intact when the fire department arrived.
The guy was drunk & stoned so, of course, he attacked the fire fighters. Flames were reported 20-30 feet high & threatening trees.
This is probably illegal in your town in the first place, but if you insist on doing this, do your homework. You need a hot fire not a big fire & you will need to attend the fire for about a day doing some stirring as you go.