I wouldn't soak the seeds in water. Fresh seeds certainly shouldn't have to be soaked. Cannabis isn't an aquatic plant. Those seeds are living, breathing and a bit sensitive; they need more than water. Excessive moisture will drown the seed or lend to disease and the seed might rot.
Personally, I'd fill the cup all the way to the top with soil-less mix, stick my finger in the middle up to the first knuckle (0.5"), drop the seed in there, cover and water thoroughly. Refrain from misting. Water again once the soil surface has dried out (cups will be lighter); which may take from a couple to several days depending on seed germination, lighting, temperature, air movement. As roots grow in you will need to water more frequently. But it is really best to just water thoroughly when you water (as opposed to misting the surface) as you'd rather not have dry spots develop.