Soaking seeds

I'm taking hints from this post. There are several ways of growing listed, and I'm going to conduct experiments to figure out which are better. But first step is unambiguous: soak seeds in water for couple days. That's what I did today: got a glass of cold tap water, heated it up a little bit in microwave and poured half of my Ficus Religiosa seeds there.
Fukubonsai says discard all floating seeds, but all my seeds floated, none have sinked by themselves. So I forced them down with my finger, but half left floating anyway.