Body disposal

I was reading something with the typical "put the body in the hole before they pour the concrete bit.

This is practically a cliche, and the void that will result in the concrete could cause the foundation to fail. Which gets things looked at. Not good.

Then I recalled a scene I've seen in downtown Portland several times over the years when they were putting up skyscrapers. Piledrivers driving pilings for the foundations.

Now, I'm not certain how they start that process, but I'm assuming they dig a hole to act as a starter, then lower the piling in and start pounding on it to drive it deeper until it is deep enough (or hits bedrock).

So it occurred to me that dropping the body in the pilot hole, with a foot or two of dirt over it ought to work nicely,

Shouldn't take long for the body to be mush and bone chips. Even if anybody was going to dig down that for to look, I doubt there'd be much identifiable left.