Generally speaking, it's not very practical to offer a dish big enough to soak in for the larger snakes - an activity best reserved for bathtubs and outside kitty pools. Stick with the large ceramic water dishes or something else that's easy to keep clean.
If it fits it sits. . . . some people like providing their giants with a water bowl they can bathe in . . . I prefer not to change substrate and water daily. I use XL water dishes from RBI (The croc dishes). They work excellent and can be cleaned in the dish washer as needed.
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Retics are my passion. Just ask.