How can I get my salt dough ornaments to dry?

[WhenDoISleep]

Salt dough novice here - DS2 and I made salt dough Christmas ornaments for a school project on Sunday afternoon. I left them to dry overnight and then baked them on Monday but only one of the sides baked. Since then I have left them by a radiator and also baked them in the oven again - but still only one side has hardened - the other is still dough coloured and feels soft. I have had them in the oven again today, but some don't seem to be hardening at all.

Is there any hope of getting the ornaments dried out enough to paint?

I put them straight in the oven once we'd made them. Worked a treat.

Very low heat in the oven for 6 odd hours

microwave

Did you turn them over to try to bake the other side?

I've never had much luck with Salt dough.