Myself, I've now got 7 kegs sitting in the tiny room that connects all the other rooms (I've got a small apartment, my brew stuff takes up 1/3 of it) but I've never worried about appearance beyond the rubber stuff that I grab on to to move them around.
To get rid of grime there, oxyclean works well. When I'm cleaning out my 6.5 gallon primary bucket, I dip the washcloth in it, soak it, let it sit for a few and then scrub. It doesn't take too much work and I get them "clean enough" to touch. SWMBO also thinks it's safe to touch.
My LHBS receives them "clean" then they sanitize them as well as pressure test them before selling. I trust them with the pressure test but not with the sanitization. I grab my spray bottle
and dump some in then connect it to the CO2 tank and squirt some through the tap. After that, I call myself "done" though one of these days I'll actually break the kegs down, replace and lube the parts and re-assemble.