Slowing the rate of flesh decay is a waste of time and also isn't great for the environment. Let the decomposers do their work and let the person's body reenter the cycle of life faster. I like the idea of being put in the ground, covered in cloth, and have a tree planted above me (a la
The Fountain).
As for the sanctity issue, who cares? It's not like Deady McDeadson is going to complain to the concierge if someone scrolls across their grassy surface. Whether you are religious or not, the person is no longer alive.