I
bath my skinks and dragons in a round plastic laundry wash tub with handles on it, I make the
bath water is about 35oC (noncontact IR gun) and no deeper than 2" for the bluetongue skinks and bearded dragons, and I do this one lizard at a time on the coffee table.
I discovered than my skinks and beardies would freak out if I took them to the kitchen sink or bathroom to
bath them in the sink or the bathtub , especially if I ran a tap in their presence. So I don't anymore.
Easier to do it all on the coffee table or floor , so if when the lizard decides it's had enough and climbs out I'm handy or if on the floor they can just climb out and we know they'll be safe from a accidental fall.
(Bathrooms and kitchens usually have very hard floor surfaces, and it's easy for a lizard (or any animal) to slip off a bench or table and land on the floor and break a leg or worse - not worth the risk IMO.)