Seems To Me....
you have gotten plenty of responses on why record cleaning machines work so well. There really is no drawback to them except their cost, and possibly the room they take up.
So I can only surmise that your bump is about trying to find justification that a hand cleaning process is going to be as good, or nearly as good as a RCM machine. Well that just ain't the way it is. Maybe it will be passable, but its not going to be the equivalent.
Now if cost is an issue, and you wnt to do this as inexpensively as possible, there are a few options. Watch the used internet sites like a hawk, and you may be able to snag an Audio Advisor Disc Doctor machine on the cheap. But they get snapped up lickity split, so you gotta have your A game on.
Secondly you can DIY, or maybe do the KAB system. A vacuum machine is not rocket science. Use a shop vac, and either put velvet on the crevice tool, or build a wand of PVC and velvet. Its a bit ungainly, but it will work.
As far as a Spin Clean, they do work, but not as good as an RCM. A record store I buy vinyl from uses one to clean their stuff. I thought it was a nice service, and certainly added value to their records. But when I got the vinyl home and gave it a play, it was still noisy. Ran it through my VPI and it got noticeably cleaner. The Spin Clean may work, but its not going to give you the cleanest records. How it compares to a wash in the sink, that I cannot say.
But as far as your opening post, I would say you have had your answer many times over.
Regards
Mister Pig