First of all, an “eschar” is a scab that forms as the result of a burn. This is, indeed, the proper term for post-treatment electrolysis crusts. Well done! However, these cannot last any more than, say, a week to 10 days (in the extreme).
What I’m seeing in your photo is “classic” hyperpigmentation. Two months is not enough time for these marks to disappear. If you have any doubt, consult a dermatologist.
These marks are not going to slough-off, because new pigment is being made and will continue to be made for the next several months. These marks are not “laying on the surface,” they are being generated and will continue to be produced (by the inflammation-stimulated melanocytes).
Actually, the pigment IS being sloughed off daily (as old epidermal cells "die"), but NEW pigment is being made and “injected” into the fresh basal cells (epidermis) every day too! The process is “on-going” until the healing is complete: technically, a year to 18 months for FULL healing … (Although the skin looks totally healed-up in a few weeks. It’s not.)
Can PIH be permanent? In rare cases yes, but the injury is generally much more severe that ANY electrolysis treatment can deliver at ANY level. I have NEVER seen PIH NOT resolve completely (from electrolysis). Permanent PIH sometimes happens when the dermis is burned away; impossible with electrolysis. But even in these extreme cases, the PIH becomes less visible in time.
If this is bothering you, consult with a dermatologist (or a qualified esthetician) and get a product (cream) that will lessen the appearance of the PIH until it resolves on it’s own (6-months or so). Such products are very effective. Get a product with “sun screen” in it, as sun exposure will darken the PIH. You will have to use this product daily for a few months.
If you want, I will give you a guarantee that your PIH will go away … I’ll even “sign it in blood!” tee hee