Since I sort of specialize in fiddle leaf ficus plants, having grown and propagated them for almost four decades, I have seen exactly the damage from prolonged heating/lack of moisture/lack of air circulation. A couple of years ago I had four large plants, all over 3' tall, shipped to me and I lost them all. I pretty much knew when I opened the box that they were "goners".
I would not use alcohol on those leaves. They have been traumatized enough. Just use water to gently clean them, bottom and top. But doing this right now is not a big thing. The last thing you need to worry about is some imperfections in the leaves. Mist the leaves twice a day. I would maintain the potting soil at slightly-moist but because the roots are probably not taking up much moisture, I would ere on the dry-side a bit. Certainly don't allow your plant to sit in a saucer of water! These plants like moisture but not "wet-feet". Don't fertilize UNTIL you see new leaf growth. Again, the roots just can't utilize the fertilizer. Use 1/2 strength, 10-10-10 or 20-20-20 when you do start fertilizing. This plant needs bright, indirect light and if it can go outside, under a large tree for example, that will be a definite plus. Just be sure the plant does not get direct sunlight between 10:00 AM and 4:00 PM.
