Cleaning......

Method 1.
Use First Contact Polymer cleaning solution http://www.photoniccleaning.com/. This can actually be done without removing the mirror from the carrier. It's also expensive and most of us like to save our money for astro goodies.

Method 2.
I have a plastic container 10x10 inches and about 3 inches or so deep, perfect. I do the cleaning in my kitchen sink with it. Get the water running at room temperature or maybe just a tad warmer.
Rinse the mirror and place it in the plastic container. Fill the container with enough water to completely submerge the mirror and put in a half teaspoon of dishwashing liquid or baby shampoo.
Rock it side to side, swirl it around, whatever, just get that solution moving over the mirror and it will loosen and remove much of the crud.