Ok. Pictures of existing products are clearly failing me here. Let me try to craft a better written description...
First of all, do away with any kind of rigid sole at all. Even the sole on that "ballerina pump". Hell, Even the soles on most of those Sockwas is much
too much. (The original sockwa is the closest I have seen so far, but they no longer make them - all the new, "improved" models include additional features I do not want).
I don't want any foot support at all. Basically, the only functionality the sole should serve is to keep the bottom of your feet clean, so you don't get kicked out of eating establishments (not that that standard makes any sense, but it exists nonetheless). Perhaps a little bit of toughness, to guard against cuts (but mostly to differentiate it from a sock, again, to avoid getting you kicked out of places that think barefootedness is unsanitary).
As far as the rest of the "shoe", I don't quite know what material would be best, but the idea should be just enough to hold the sole on to the bottom of your foot. None of this fleece lining, neoprene-breathable-mesh stuff. And bows are right out.
I'm thinking like a moccasin, only scaled down to the most minimal conceptualization possible.
My memory swears that I've seen such a thing. But my search-fu contradicts this.
Maybe it doesn't exist. Maybe I wouldn't be caught dead wearing it if it did. (After all, small = dainty, no? Guys are supposed to wear boots
Or maybe I should just crusade to get barefootedness to be more accepted. That might be easier.