Micro-Fiber cloths are supposed to be used with pure water only. No surfactants, soaps, or chemicals. Further not all micro fiber cloths are made the same. The best ones are dual polymer split fiber. Specifically they are a blend of polyester and polyamide. The smaller the split fiber the more powerful the cloth also. I will show you a couple pictures here of what I am talking about.
I love pictures because they can help us understand so quickly.
The cloth I have chosen to work with is called the E-Cloth. Here is a link to the company that sells it. It is also great for detailing around door stickers, or just touching up mirrors and such. Great to sell to your customers in a zip lock with your contact info also.
I have an article I wrote in my blog about micro-fiber cloths too. The link for that is;
There is a video link on that blog post too which is great for learning more. But the bottom line here is to only use the best cloth made specifically for glass, and just use water. Most times a very light mist is all you need.