Paying to empty WC in Campsites

Does anyone know if you can simply turn up at an Irish campsite, and pay to empty your chemical toilet, and refill your water tank ?
We did this a few times in the UK, and most sites had a fixed charge, up to £5 if I remember correctly.

This year especially I would say that would be a definite no due to the present pandemic.
If what I hear is correct campsites are laying down a minimum stay and they say this is to reduce the turnover of people coming and going.
Of course greed will also be in play,either pay through the nose in some cases or they will ignore you.
There are other places to empty your loo and get water.