Yep, they bury the eggs. I have Eco Earth for soil in my tank and that's where they lay them......most of the time. Sometimes they'll lay eggs in the pots of the live plants I keep in the tank with them too.
Ye I heard they like pots I'm using bark substrate should I change to a softer substrate been told they are easy to breed, think in tryin a bit to hard.
I haven't tried bark, just coco mulch for them to lay their eggs in. And to be honest, this year I didn't incubate a single egg. I let them all hatch naturally in the cage where they were laid and this season I produced some of the best looking babies so far. The trick is getting the babies out ASAP so the parents don't eat them. Lucky for me I have well fed adults that don't look at the babies as food!