I use a cricket bowl. But they're eating fruit flies right now. I don't really understand how having 4" of water adds "hassle and pressure". They have a ton of vines to climb around, and they would be over much more than 4" of water in the wild.
If you personally do not like the idea of using water as a substrate that is perfectly fine, but that does not make this enclosure "unsuitable" for these frogs.