Who'da thunk there were so many Partridge Family fans?
Anyway, a brief, slightly more sober analysis....
After several days I've examined the record closely. Despite my fear of Armor All being a dust grabber, there is no appreciable sign of dust, nor is there any filmy residue. It was very difficult to thoroughly get that **** off though, so I'd probably never use it again.
A brief yet excruciatingly tedious listen of the album reveals no obvious degradation in overall sound quality, so I think if any of these chemicals are truly detrimental to vinyl I would have heard it, since I left them on for four hours in undiluted concentrations. Just as an aside here, while I am certain I lack a "golden ear", I am a video editor by trade and I spend a lot of time listening for bad sound- I can hear 60hz hum when a power cord crosses a mic cable, when a forklift rumbles in the background of a voice over, a wireless mic whose transceiver battery is getting weak. I'm pretty sure if the signal got bad, I'd hear it....
The bottom line is that all three substances did a decent job of cleaning the album. Personally i'm sticking with water/alcohol/dawn because it is A) cheap, and I'm a cheap bastard and B) relatively mild and not likely to create any long term damage. The more expensive cleaners may work better (or not) but I don't think you'll harm your records with the DIY solution.
I won't use Windex simply because it has a known effect on Polycarbonate- if you use it on clear plastic the plastic will fog, and do so fairly quickly. It may not have any effect on PVC, but not worth the chance to me. If you do use it, I'd recommend a good rinse when you're done.
Armour All? Well it certainly made the record look pretty! Really hard to rinse off though, and while I don't feel any film left on it, I wouldn't swear that there isn't any there. I'm concerned what is there will muck up the stylus more than affect the vinyl itself.
So your friendly neighborhood drunken redneck recommends sticking either with the expensive cleaners OR a mild DIY blend, whichever makes you feel good about yourself since I doubt there is much difference between the two. You can be the audiophile "must preserve every atom of sound" type or you can be the cheap as$ "look what I bought and cleaned for only 25 cents" collector, as long as you are happy in your role.
Look for my next experiment on static control devices.....