I like to soak them in a coffee cup of Distilled water for 12-24-48 hours
on top the water heater with a cover on top the cup.
the theory behind it is if the seed sinks to the bottom of the cup
it's a good seed, and ready to go in to your damp paper towel in a zip-top
bag in a warm dark spot until it sprouts.
The seeds that don't sink, either are bad, or have water tension and don't want to sink.
push the seed under the water with your finger, and give it another 12 hours, or you might have to scuff the seed to get it to take water.
I've noticed that it's a little quicker this way to get a seed to sprout. Most seeds i can get to sprout in 36 - 48 hours.
Try it both ways.
another thing you could do is soak the seed in a cloning solution instead of plain water.
I've never tried it, but I heard it works pretty good.