I never tried to incubate chicken eggs either of those ways but I have incubated hundreds of reptile, primarily snake eggs that way. I tried these methods when I first started to breed snakes and turtles back in the late 80's.
One method I did was to have water on the bottom of a fish tank with a heating pad, usually on low underneath. I used bricks and a wire platform and then placed small rubbermaid containers on top of that with the eggs inside. I also did a couple other methods including using vermiculite/perlite for moisture instead of the water and also depending on the type of eggs I would sometime not even use the heating pad since the room itself close to the ceiling was always very warm since at the time I used to heat the entire room rather then individually. You can easily manipulate the moisture content by partially or almost completely covering the top.
One method I did was to have water on the bottom of a fish tank with a heating pad, usually on low underneath. I used bricks and a wire platform and then placed small rubbermaid containers on top of that with the eggs inside. I also did a couple other methods including using vermiculite/perlite for moisture instead of the water and also depending on the type of eggs I would sometime not even use the heating pad since the room itself close to the ceiling was always very warm since at the time I used to heat the entire room rather then individually. You can easily manipulate the moisture content by partially or almost completely covering the top.