Keep the damp napkin in a Tupperware container in a warm dark place is the best you can do, sometimes it take more then overnight depending on fertility of seeds the longer they go, well the less I've had luck with but I have grown some amazing weed on seeds tgat took eight days to open, I had a couple pop after two weeks last germination. I had just left the seed in the dark to see if they would after getting the first ones out and growing.