Just wanted to post an update. After beating the game, I uninstalled, wipe preferences and re-installed and played up to level 10.
I found a bottle of swirling mud within minutes of hitting 10.
So it's possible that there might have been an install issue that prevented them from showing up. I also noticed through play through tons of other items I'd never seen before (and I'm a pack rat and keep *everything* so this was a big obvious sign to me something wasn't right with the first install)
So for the original post, might want to try re-installing, as it *could* possibly be a small bug only a few of us seem to suffer from.
(Either that or it just was pure dumb luck I never found one in my hundreds of hours of play-through the first time. Either way, I'm happy my problem is solved!)
