Hi Leon,
I think, like you, most people end up with the plastic boxes – as ugly as they are, they do work well.
we put several layers of brown paper on the bottom of ours, which makes it easier to simply lift the poo and soakings out very once in a while, depending how dirty they get, and these can go into the brown recycling bin.
It does seem to be the case that hogs prefer an untidy environment to a pristine one, but we have always considered the poo deposits to be a sign of gratitude.
having overwintered hogs for a number of years – I can say with a degree of certainty that the poo activity is used as a communication tool – and they can be very creative about it as well!
