the lines that look like cleaning are scrapes in the slab. Yeah I have never heard of them and can't find anything on the internet about them either. The coin has some toning that looks blotchy in hand.
That is not the reason we think the coin has been cleaned – the coin does not look right and the color is off.
I agree that the coin could be cleaned and that the color appears off, but it could be from the photographs. I don't think we can say definitively that it has. Given it is in a third tier slab and probably was sold as "certified" it certainly wouldn't surprise me.
Areas of Interest: Original classic gold coins from the Southern mints (New Orleans, Charlotte, and Dahlonega); Carson City minted Morgan Dollars, early copper; high end, quality U.S. type coinage; proof like and deep mirror prooflike coinage; toners including Peace Dollars and classic gold; and cameo and deep/ultra cameo proof coins from 1936-1942.