dct147 the standard break in method does not require you to run idle for 3litres of fuel, throughout the entire break-in process you only need to do a max of 8-10 tanks. To run the engine for excessively long periods of time at idle like you LHS reccomended is detrimentle to your engines internals. I have never heard of anyone using 6 litres of fuel to break in an engine- your lhs just wants you to buy alot of fuel.
A good (standard) break in method would be:
*1 tank at idle.
*3-4 tanks running at low speed (A few blips of the throttle to clear engine of fuel).
*Lean engine a little.
*2 tanks running at medium speed.
*At this point you can begin to tune the engine for high speed running.
After 7-8 tanks you can start to lean the engine out. There are many different oppinions out there on break-in but i think many would agree if you follow a method (similar) to that youll be trouble free.
Tuning adjustments should be done at 1/8th turn like you said, a reasonable amount of smoke should be visible from the engine during mid-high speed running.