Has anybody cleaned their radiator with CLR ?

[MountainGoat1966]

The copper/brass radiator in my 84 is due for a good cleaning, the tubes flow very little coolant.
I can't afford to replace it, and having a radiator shop do a cleaning job would require two 130 mile round trips, since it'll most likely be the next day or so after I drop it off until it's ready.
Plus the cost of the shop to rod out a three row radiator.
I'm tempted to make a cap to close off the hose connections, get three or four jugs of CLR, and clean it off the truck.
I'm not sure about running the stuff through my engine block, even though there is nothing aluminum in it, so I won't do it while still installed.