I had the same experience, very similar to what manXcat describes. I went through two distinct phases of building external calluses that had a lot of dead skin that could catch on a string, then that kind of peeled off. I am several months further along now and just like manX says, you can't really see the calluses on my fingers anymore. The calluses are there, but not visible; just a thickening of the skin on the fingertips. I never tried the apple cider vinegar trick, but sounds plausible.

If you do trim the skin be sure to only trim dead skin. manX emphasized this, but I mention it too because it is really important. Trim too much and you will expose tender new skin and it will set you back.