For only $2, I certainly would have picked up that pan too. The LL Bean Acorn pan is less common than other JW made pans.
I have plenty of JW muffin pans, all of which I have cleaned using a combination of methods. Once these pans have been used for baking, the integrity of the silver non-stick coating needs to be monitored. The problem with a used pan is that you don’t know how the pan has been treated. Looking at the photos, the black material on the bottom looks like a combination of old seasoning and rust. The tricky part of that is trying to scrub with a non-metal brush to remove that material without removing the coating. The other variance in coloration you have on the surfaces looks like some flash rust may be developing where the coating is wearing away.
Lye is not friendly to the non-stick coating. Neither is electrolysis. After long periods (and I mean longer than a couple of hours), the coating can start turning dark, depending on the strength of the lye used. After electrolysis, the coating may darken, or it may even turn into a mottled looking surface.
If you don’t have a lye bath, I would recommend letting it soak in a concentrated solution of Dawn dish washing soap, and scrub it frequently with a nylon brush. I would not recommend using oven cleaner; since, the process leaves the lye on the pan for too long, in my opinion.
Soaking the pan in a diluted vinegar solution may help with any rust. Follow that with another soapy scrub.
When it comes to seasoning these (and also using them), the lower the temp, the better. A can of non-stick cooking spray helps getting oil into all of the pattern lines of the pan. I use a maximum temperature of 350 F for an hour when seasoning. I do not bake over 350 F in these pans either. Trying to season at a temperature above 425 F can negatively impact the coating.
When faced with a pan with crud on it, I recommend a soapy scrub first, then place it in a lye bath, monitoring it every hour until the material is removed. The less time in lye the better.
My advice for people who want to buy these pans is to look for pans in the best condition. They are tricky to clean, but the less gunk at the get-go, the easier your job will be. Avoid JW pans with material burned on them or those badly rusted.
Burned-on material is the toughest thing to remove from these pans next to bad rust.
The coating JW uses has changed over time. Each pan usually presents its own tricks to cleaning.
I hope some of what I listed here helps. Feel free to ask more questions. At least the inside cooking surface of the cups looks good on your pan.
