Greasy sand

Also known as "moist sand". It's the act of digging a hole in a pile of sand (like on the beach etc.) taking a shit in the said hole and covering it with sand. It can be used like a trap or just for fun.

...also mixing sand with grease...that works too... even tho I don't know why you would do that.

-"Man, I was on the beach yesterday and I had to take a big dump but there was no potty around so I dug a hole and done my business."

-"...Ah yes, the GREASY SAND..."