I've been doing incubation in the "substrateless but not really" fashion as follows:
Have a normal egg tub with vermiculite etc. So thst isn't really "substrateless", but put a light diffuser between substrate and eggs.
I was taught to do this way and it worked so I never changed it.
I know that all you need is water in there, but the vermiculite I put there just to stop the water splashing if I need to move the tubs.
Now, someone suggested I use something like a sponge, those for aquarium filtering etc, instead of vermiculite, or even a towel. So I don't need to deal with vermuculite. Will this work?