I agree with SandAway.
All of my friends know. They know what I did, they know it's why XH divorced me, they heard me eat humble pie as I personally apologized to each of them for lying and putting on a false persona for 5 1/2 months while I was cheating, and for hurting their friend (XH).
Putting this kind of crap on Facebook or the equivalent makes everyone involved look like a drama queen. (Gender-neutral.) IMO, it will likely not have the intended effect (which I assume is to humble you and maybe also allow your BW to find support). IMO, it will more likely have the effect of appearing as though your BW is intentionally forcing you to humiliate & emasculate yourself and make her look like a pity-seeking victim.
I'm NOT saying that's her intent. Not at all. But that's the way the immature (IMO) nature of social media works.
Edited to add: I don't disagree with confiding in select friends of the marriage if it will be supportive to you and your BW. I just don't think a public free-for-all such as Facebook is an appropriate venue. Me: XWS, 30s, 5-month EA/PA in '09-'10
Husband: XBS, 40s
Married 2.5 years
Reconciled and remarried.