As I mentioned elsewhere on this forum recently, I had better results when cleaning my mirrors by simply filling the sink with water and a small bit of detergent (as advised in Mike Salway's article on here), then letting the scope soak in it for 10-15 minutes. Then, I took it out, rinsed it with tap water first, then rinsed it with demineralised water. I did not touch the mirror surface with anything to clean it. My mirror had quite a bit of dust and some mildly-greasy gunk on it and the above method worked a trick. I'd tried using cotton balls on it previously to clean it, but they left streaks. So my advice is to just soak and rinse first, and see how the mirror comes up, before touching it with cotton.
