<VV> Muriatic Acid Vs. Phosphoric Acid

[rich dixon]

I have read about both of these acids in the Corvair tech guide, does anyone have any experience with either one of these. 
 
I want to clean up some half-shafts and suspension parts. Is Phosphoric acid easily found , if so where? Which one seems to work better? 
 
What's the mix ratio of water to acid on the Muriatic acid. Once dipped in the Muriatic acid, what additoinal prep is needed other than washing them off prior to painting. 
 
Thanks.
 
Rich