Take the radiator and hold it up to the sun.

Peer through the fins...........see all that crap? That's got to be eliminated before you reinstall the radiator.

The best option is a commercial condenser cleaner with some compressed air and some patience.

Most of the cooling problems with the engine are a result of poor airflow through the fins.........they are extremely close together and harbor all kinds of foreign material that is not easily dislodged without a powerful chemical treatment.

Cleaning both sides of the radiator accomplishes basically nothing.