make the bag of holding something along the lines of a regular porta-potty.
the hole itself is covered with two concave ceramic slates (that have a permanent 'clean' type cantrip cast on them) that form a hinged bowl that is locked on the sides.
when you are done with your business, simply twist the knobs holding the slates in place and the um oderferous gift is dropped into the bag of devouring. Thanks to the clean cantrip placed on the slates, you don't even have to wipe them down.
Conversely, you could make this a specialized bag of holding. If you don't know the correct activation word, instead of neato items popping into your hand... you well get a fistful of um... offal.
the hole itself is covered with two concave ceramic slates (that have a permanent 'clean' type cantrip cast on them) that form a hinged bowl that is locked on the sides.
when you are done with your business, simply twist the knobs holding the slates in place and the um oderferous gift is dropped into the bag of devouring. Thanks to the clean cantrip placed on the slates, you don't even have to wipe them down.
Conversely, you could make this a specialized bag of holding. If you don't know the correct activation word, instead of neato items popping into your hand... you well get a fistful of um... offal.