I think patience would be a good thing to practice.
I'm imagining a pile of squash bits, tomato cores, and coffee grounds...
There are any number of articles on hurrying the process... But... little point in doing so.
At my house, plants pulled from the garden, blemished tomatoes, squash vines that have played out... all that stuff goes to the chickens... what they don't eat today, they keep turned until it becomes garden gold.
If your BIL were to toss some garden soil over the compost that he has... Then, he could stop looking at it...
I suspect that the main problem is that the pile is small.
