I recall that, “thunder pots” were used in the days of outhouses. Big ceramic coated metal pots that could be used indoors and carried to the outhouse during the day.
They were called thunder pots because of the echo effect of passing gas while using them.
One could use the plastic grocery bags to line a pot and then remove the contents to a better location (bury them in the yard or burn the contents in a metal container) at a later time. This was how things were done prior to indoor plumbing.
Saw a you tube vid showing how to take a 5 gal bucket one of those kiddy swim noodles and plastic bags and have a comfy portable place to go