From my experience the best way to germinate a weed seed is by dropping it into water for about half a day and keeping it out of light. It probably doesn't matter if the seed sinks to the bottom of the water or not (though maybe it is best if you force the seed to sink to the bottom of the water).... let it soak for half a day, then after half a day, place the seed onto a very wet bunch of paper towels (use very warm, not hot, water) and fold the paper towels over the seed GENTLY, leaving lots of room for the seed. Its probably a good idea to not let the seed become entirely submerged in water at this stage, and its generally a good idea to put it in a warm place.
A water cabinet? (the place where the hot water is) If it gets cold at night, then its probably wise to keep it away from the windows at night.