[Marrk]

Think about it, you might be loosening the dirt and grime, but then think about where it'll be going now that you loosened it up.

Yes... straight into a dirty combustion chamber and out the exhaust never to be seen again. Most of the crud is recirculated oil vapour from the engine breather which is tied into the turbo inlet to be burnt with the air and fuel. Cleaner emmissions and all that!

There will be no problems putting cleaner past the throttle flap, but don't flood it though as it can flow past a open inlet valve and wash the oil deposits off the cylinder wall etc.

 

[Marrk]

Yes you can, no problems buts its easier if its taken off though.