I used the XL Zoo Med Reptile Ramp Bowl. It was big enough but not too deep. It also has a ramp for easy exit. I would check the bowl on a regular basis (a few times a day) to make sure the bowl was full and remove any babies that were in it.
I use a 10" diameter plant pot saucer or, in my larger enclosures, non-perforated plant seed trays measuring about 12" x 8" x 2.5" deep. These are my preferred. Always conscious of drowning so put clumps of moss or pond weed eg hornwort in, or a flattened pebble ramp. This also serves to provide some hiding places should I miss a couple of youngsters thus reducing issues re cannibalism. The bigger the better really but not too deep. Mine are limited to fit into the main enclosures. As MasSalvaje says, check the dish regularly throughout the day over a number of days.
Dave I've seen these videos too. They never show the drowning salamanders do they? Believe me, captive animals lose the edge I reckon. Maybe they become less motile or less active but some are prone to drowning. Why take the risk? There's no need to. I'd also keep in mind the size differences in the various subspecies eg my Alfredschmidti compared with my orientalis. Plus, it's much more convenient emptying, cleaning and replacing water in these smaller containers than a large one.
I guess the females can't always find perfect conditions in nature and have to make do with second best some years, even if they risk drowning themselves.
I do agree that some caudates take unatural risks as a result of captivity. The "begging" to be fed behaviour is a good example of this, in the wild it would be a good way of getting attacked or killed, but they seem to throw caution to the wind and think with their stomachs.