I accidentally let a layer of Bar Keepers Friend on my stainless steel pot sit for too long (my first time using it…my go-to is usually Bon Ami but I decided to give BKF a whirl). Is there anything I can do to fix the pitting? Or, more important than the cosmetic aspect, is the pot still safe to use? 
That’s some powerful $#!t.
Have you tried one of those stainless steel “scrunges “ and elbow grease? Usually works on all-clad for me.
Oof, how frustrating. I think Pilgrim’s suggestion is worth a try. Though I might first start with one of those plastic-ish scrubbie sponges like Scotch-Brite (yeah, dislike using those but sometimes I don’t see a good alternative).
Other avenues might be posing the question to manufacturer of your stainless steel pan and/or BKF itself. This must happen to other people, wouldn’t you think?
If I have any better ideas I’ll post ‘em here.
Check Reddit - someone has definitely done this before
The pictures does not look like pitting.
Your pictures resemble discoloration.
Either way, cosmetic and safe to use.
Hopefully and probably not full pitting. You may able to use Bar Keepers Friend to fix this. 
Was something burnt on? I agree that it looks like food residue that a steel scrubber might help.
To me that looks like discoloration. I have had that in some of my stainless steel pots. I just had this recently with some baked beans.
And though you might be gun shy at this point, I suggest you use the Bar Keepers Friend again, and elbow grease. Mine come out pristine!
If the problem is discoloration rather than pitting, a paste of baking soda and dish soap might do the trick. Rinse well before (to remove any residual BKF) and after scrubbing (because baking soda and soap aren’t tasty).
Will be interested to know what the remedy turns out to be.
I took a closer photo, and to my eyes, I can see the layer below the surface. Which I think is “pitting?” (Auto-correct stated “pitying.” Yes, I am feeling some self-pity, Ms. iPhone.)
I’ll try to clean the “discoloration” and hope that I’m not removing a layer of steel. Well, it can’t get any worse.
Make a paste using baking soda and water, apply and wait 4-6 hours.
Your pan has burnt on food and scratches from abrasive pads.
Pitting is small holes or pits, often caused by adding course salt to cold water, then heating to a boil.
That isn’t copper core we’re looking at, is it?
Doubtful. It’s a simple Cuisinart but sturdy and reliable that my FIL got us as a wedding gift some years ago. I don’t have to look it up right now. I’ll look later.
I would try some white vinegar and a scrubbie. I have found that white vinegar works wonders on SS discoloration. You might even try heating the vinegar, too.
