Cobbers,
This is how I clean my mirrors and I have never had a problem with it.
Once you have removed your mirror give it a blow to remove the coarse debris of the mirror surface. Compressed air is your best bet, if you use a blower brush please remove the brush attachment as it can drag crap across the mirror surface.
Next place the mirror in a
clean basin or sink and prepare a solution of warm water and a small amount of dishwashing liquid.
With some cotton buds
gently clean the mirror in a radial action, ie from centre to edge until you think the mirror is clean.
As soon as you have completed the cleaning rinse the mirror with distilled water then put the mirror on it's edge to drain. At this stage you may use a hair dryer on a gentle setting. if there is still crap on your mirror repeat the process.
I hope this is of help.
