What is a burial by acclamation?

Maybe means Memorial by acclimation, which is singing.

As near as I can figure, it means to not embalm, to allow the body to decompose naturally.

Desmond Tutu was cremated with a process called aquation. Instead of burning the body, it is dissolved in water. Evidently, it’s more environmentally friendly than burning. I have no clue how it’s done.

^Seems like that would take a while.

During cremation, some bones don’t burn and must be pulverized in some sort of a pulverizer/grinder. Perhaps the body is processed in some kind of water processer, like one for food, where the processing occurs with water and the bones can be ground. However, a wood chipper would work quite nicely.
It could be that he will simply be buried unembalmed, in a simple wooden casket that has been filled with water. Or buried in a place that is below the water table. Or buried at sea.