Tin foil troubles

I don’t have A/C, so this summer I tried putting tin foil up on my windows to block out the heat. It definitely helped, but it left a nasty mess on the windows after I took the tin foil off this week. Baked on condensation and some mold probably.

I did all the basic stuff, windex, vinegar, hard water spray, razor, steel wool. I got MOST of the grime off and the windows look super clear again, but there’s still some stubborn spots. If I run my nail over them, they definitely have texture, but they don’t want to come off.

Here’s a before and after of this mess. The after pic is hard to tell, but there’s definitely still grime on the windows.

The windows are crappy single pane from a 1960s building, if that changes anything.

Help! What now?