injector cleaning 1991 Audi 90

[Mark Zvolanek <mzvolane@sydney.ipex.com.au>]

Audi owners!

Does anyone know how are the fuel injectors suppose to be cleaned?
Dealer service manager offered me injector clean service which involves:
injector cleaner pump connected into the fuel line then
they let ~500ml of injector cleaner circulate through the fuel injection   
system under pressure for at least half an hour.
Is this how it gets done normally?

The reason I ask is beacuse this service was offered me as "good will   
gesture" valued at AUD$65.
Dealer has done a repair of ignition lock about a month ago and they also   
replaced steering lock.
Since then I have questioned the replacement of the steering lock   
~AUD$150 as I could not see anything wrong with it. The service manager   
was trying to convince me that the reason for the replacement was some   
pin inside the steering lock assembly which was missing, but he could not   
produce or show it (the pin) on any diagram. Does anyone know exactly   
what parts are inside the lock? The parts I know of are key lock barrel,   
pin (not the one that was missing but the one originaly broken) and   
steering lock itself. Is there suppose to be a second pin somewhere in   
there?
Is he trying to shut me up with his good will gesture?
Mark Zvolanek