Is a torque wrench absolutly essential when changing pads?

[DJMK4]

Or can you just use a normal wrench and somehow gauge it yourself?

Also what about cleaning parts before putting back together?

 

[DJMK4]

Whats this copperslip (Slipping) all about then? think its the only I think I need to know before I get to work, and is there any preffered cleaning fluid to use? or can I use something else.

 

[DJMK4]

Cool, cheers for the info