I also use this product. You can also find it on the Bay
http://www.ror.net
ROR was shown to me at scope city in SanFran when picking up some cheap scope stuff when on holidays. Fantastic gear and great on the eyepiece as well. Does not leave marks at all. I use a soft lense cloth that I use once only and then discard.
I have removed my corrector for other issues and feel this should only be done if you really have to. Cleaning the outside really does not need the added risks..
Saying that, each to thier own.. If your fear it and lack confidence....Don't Do It
Mardy