Old Q, but anyway.
Some of my datura go mouldy in the pods while still on the plant. Mostly Datura inoxia, but some times the others too.
No idea why, but it doesn't affect the germination at all when I planted them straight away, or stored them 2months then planted them.
I only store the good ones now just in case, and if the pod has any visible mould it gets replanted immediately or dumped.
I tried washing in 6% peroxide, and they looked fine for about a month in storage, then they went mouldy with a different coloured mould?
Still germinated fine, but yeah, looked pretty sickly, and those seedlings didn't grow well eventually getting eaten by bugs.
They were not healthy compared to the others with clean seeds.