I use a drip wax (Squirt), but even then the chain gets more or less black. But nowhere near like it does with oil or synthetic lubes. My hands will still get dirty if I handle the chain and I can still get chain marks on the back of my leg. But even these are no where near as bad with the drip wax.

I think I read somewhere that this black may be from car tire residue on roads. I don't know about that, but it's not unreasonable to think there could be something on road surfaces that causes this. Even car brake dust.

We all have different requirements. I happen to ride in a very dry area. I never ride in the rain as it's simply too easy to avoid a rainy day. The Squirt drip wax works really well for me. Maintenance is very easy. When I re-lube about every 200-300 miles, I first wipe the chain down with a rag slightly dampened with mineral spirits. The idea is to just get the gunk off the outside of the chain where it does no good anyway.

Then I put a drop of Squirt on every roller, one at a time. That's not as tedious as it sounds. But many just stream it on while back pedaling. I run the bike through the gears just to spread any excess on a range of cogs and a light wipe on the outside of the chain to remove excess, before the drip wax dries. That's it.

With this approach I never feel the need to clean the drive train of build up beyond what I described. While there is a little dirty looking wax on the cogs, I generally don't feel any need to try to remove it. I can put several thousand miles on a chain and have no measurable chain stretch. And when I twist the chain, there is none of that grinding sound from grit. So, it seems to be doing a great job of keeping it lubed and keeping the grit out.

Anyway, there are a lot of ways to skin this cat, this is my way.