I've searched and read the myriad of posts concerning this topic, but no one has yet to ask this question so here it is.

Should one grease the splines on the freehubs at all, to prevent the cassette from seizing or anything like that?

You dont need to, i suppose it wuold not hurt but i would not bother. I have had no problems and i have never greased it. It wont sieze anyways

I don't know if it helps, but I don't see how it would hurt. I use a thin film of water resistant marine grease on mine.

Ever heard of a dirt magnet?

Is that like a left handed smoke bender?

Thedle: once you actually take off the cassette you will see why there is no
need for grease on the hub splines. There is enough dirt and grease off the
chain to make a mess down there without bollixing up with grease, as Sydney
says. Note that the splines have one area where the splines vary in thickness
wide/narrow. This is to register the cassette cogs in a constant relationship.
Steve