I have used the radiator + pump. It will not work if you use an alkali like KOH or NaOH. Either one of those chemicals will destroy the aluminum in the radiator. I guess if you can find a SS radiator then it would work pretty good. Also, the radiator must be electrically isolated from the current in the electrolysis unit. I never tried the radiator with baking soda as my radiator only lived for 3 days with NaOH. The NaOH destroyed it in a hurry.
2006 Ram, 5.9 cummins HO. 4 cell design, 1.5 LPM@30amp, 24.3 MPG