In case anyone is interested in what a sponge baffle looks like on a Marineland Eclipse Hex 5 gallon, here's my setup:
I used a thick Aquaclear sponge and cut it to size. Both of the outflow channels are covered by it.
And you can see the bottom of the sponge sticking into the water here:
It took a bit of adjustment, but now the water is still enough that you can see the reflection of the rubberband and plants. My betta also started to make a bubble nest off the sponge of all things XD
So if a plastic baffle doesn't work for you or you're afraid of injury (because it can happen), I highly recommend a sponge baffle :)