Congrats on those eyeballed mercs. Most of us need a detector to pull a merc, unless you're a CRHer or know someone at a bank or a cashier at a store. I haven't dug either of those date/mint marks yet. How do you clean them with peanut butter? Forgive me I am not a pro at cleaning coins. Is this a recommended process that does not affect the coin?
To clean the crud off the back, I rubbed peanut butter on it and let it sit for a few minutes. Then I rubbed it off with paper towel. Took some elbow grease, but it worked great. By the way, I think that crud was actually very old chewing gum!
Peanut butter works great on removing anything sticky like gum or price stickers on items such as CD cases or anything that isn't porous.
I also gently rubbed them with wet baking soda. Works better than the baking soda and aluminum foil method. Might be a little abrasive, but those two coins were toast anyway.