To stop from bursting into flames..

We always soak our wooden pieces in warm water for about 5-15 minutes before we bake them. They might not always burn, but there is a chance they could, so why not :)

The nickel is only there to weigh down the wooden plate, it floats :P

Then let them dry in a nice sunny spot until you're satisfied with the water content they hold.
You can also towel dry them, doesn't matter.