I've always applied a thin coat of grease on the freehub prior to installing the cogs. Been doing that for 18 years as part of the wheel assembly routine after cleaning the cogs. Considering that the locking ring is torqued 45nm, there really is zero movement of the cogs within the freehub. I'm now thinking that the thin layer of grease only attracts dust particles in the freehub assembly and has no other benefit. Just curious to know what others do. TIA.

i've never used any grease there

the parts aren't moving wrt to each other and there's nothing threaded to bind, so, as you say, it just seems likely to cause dirt to stick

i do put some antiseize on the lockring threads though

If I lived by the ocean, I'd consider it. Otherwise, it just makes a mess.

Thanks!