Cleaning: What is the best way to clean the internal elements of the lens?

I bought the old lens nikon ais on ebay. It was really cheap. It turns out that it has some fungi that grow inside it. Do not worry, I take it apart and clean it. I used alcohol, 98% solution to clean it. It turns out that she shed a bit of the coating. I tried cleaning with glasses solution. But it leaves stains and is not perfectly clean. Before ruining another element of glass, what solution is recommended for this use?