chain cleaning

[simonm]

I know nothing about bikes except that the copper on my bikesafe course said my chain was minging.  A small amount of research later and a slightly squashed finger and it's done.  I used paraffin, a rag and toothbrush and used some scottoil afterwards to relube.

Two pictures, before and after. Was there any point ? Any tips ?  How do you clean the side of the chain you can't see ?

Cheers