Cleaning a Very Dirty Mirror

I have a 14" Dob and the mirror has been sitting for 3 years in its light box in the garage. I want to clean the mirror which is quite dirty. I have basic mirror cleaning instructions but am asking if there are any special considerations or methods I should use for a dirtier than normal mirror.
Mike

Hi Mike, rinse it under the tub faucet with warm water very well, let set with a little dawn in the water that stays in the center and swirl it around the mirror by tilting it side to side. Let set for no more than 5-10 minutes and rinse hard again with a lot of water. Repeat if required and then do the normal cleaning routine.