I've used domestic glass cleaner containing isopropyl alcohol (Nilglass) on my iiyamas, every week, for several years. There has been no noticable degradation in the coating on either of them.
The secret is to use, extremely soft cotton cloths which have not been washed with fabric softner.
If you really want to avoid alcohols, then distilled water works almost as well. A scrupulously clean cloth is just as important.