Not sure I’d put 1” of water in the tray.
When I used them I put them in a closed bottom tray and just kept them damp from above with a hand held bottle sprayer. I used them to start tobacco plants several years ago. I’d forgotten about that and hubby reminded me. The potmaker got covered up with something in my gardening cabinet and I thought it had either been thrown away or ‘lost’.
I’ve also used empty toilet paper rolls. The cardboard ones. Fold the bottom in on itself after you’ve made a couple cuts with scissors. I put 1 dollop of Elmers glue on the flaps to hold them. Those did fine btw, just like peat pots. Just make sure you cover the top edge with dirt so it doesn’t wick the moisture out of the soil when it gets hot.
What a great idea.