Best way to clean aircon condensor? Lots of road grime.

[Circlotron]

Gradually getting the a/c going. Replaced 30 Amp fan fuse so fan now goes but I notice it is pushing hardly any air through the condenser. It all seems to be blowing back through the fan to the extent I though it was actually rotating backwards, but it's not. Basically, there is 500,000 km of road grime packed in all the wiggles and fins and tubes stooping any worthwhile amount of air getting through (would also explain why the clutch-fan drones away on very ordinary days, trying it's best to suck air through).

So... what's the best stuff to dissolve all the puke that has built up in there? I definitely don't want to pull the condenser out and I don't want to pull the radiator out if I don't have to. Hope I can just pull the fan off the front and squirt it with some kind of solvent and hose it through.

[VR38]

I pick out the chunky bits and then soak it with caustic oven cleaner followed by a strong hose if degreaser won't loosen it.
wash the mr muscle off any painted surface straight away.

[VR38]

BTW if the radiator is as old as the grime then budget for a new one if you are getting temp problems.