I played this when I was a student. It cost me an awful amount of work to finally get it to a point where I considered it to be presentable, but even then I wasn't really happy with it. I have no inclination to work on it again: for me, this is one of those pieces where the musical content doesn't justify the amount of technical work you need to put into it. Chopin wrote lots of more interesting stuff.
If, however, you are hell-bent on working on this étude, my advice is the same as what Marc-André Hamelin says in this video when talking about Islamey:
Practice really, really, really slowly. And in chunks. Do chunks of only one measure at a time, stopping on the first note of the next measure, at a speed where you make no mistakes at all. When you can play each measure comfortably without mistakes, try chunks of two measures at a time.