I've never tried either but from the seed starting that I've done in the past, most seem to need bottom heat to get going. There are some plant seeds that need cold stratification but I don't think that's the case with these. Still, it's often a race between getting germination and the seed rotting.

Sometimes difficult-to-germinate seeds can actually be started in a ziplock with a wet paper towel or damp vermculite and once a root forms, the seeds can then be transferred to a container with potting mix.