PH
There is this other methods that will not also work well, that is applying the powder in the mirror, and then trying to wipe it out with tissue paper this will not really help. The reason I am saying this is that you will still have some smear.
So I will love you to follow this siomple step and get through those hassle in you cleaning.
1. Boil some water either with kettle or a small pot
2. Let the water cool to room temperature
3. Use it to clean you mirror, note the cleaning should be done in a round motion to avoid smear
4. To Get better and perfect cleaning of the mirror, poor the water into a spray bottle
5. Add some cleansing agent like dish washer e.g morning fresh
6. The use a cloth with micro fibre and do the cleaning while spraying the liquid unto the glass
