I took off the inlet pipe - the big plastic one down the back off block. Re reading the instructions though it says to remove the outlet pipe and my mechanic friend has said all the carbon / gack tends to gather on the out.
bent rod would mean one of the cylinders isn't getting all the compression it should, but then the more I think about it if 1 cylinder had low compression it would always be a problem? not just on startup from cold?
Sure Steve will enlighten a bit when he can get online...
You put it in the wrong side

As your friend said the vain actuators are on the exhaust side and clog up with soot so they don't operate correctly resulting in over boost. The cleaner dissolves the soot allowing the gains to operate.
I agree with you that if you had a bent rod it would affect it all the time not just on start up.
What happens when you start the car after its already warmed up? Does it start fine?