Hi Sprayman,
Your process is good enough, don't hit the concrete with any pressure think " glorified rinse"
The material though, muriatic is no good.
Muriatic should only ever be used for the purpose of etching for coating prep.
Muriatic is hydrochloric acid.
Use something a bit more detergent, Prosoco Vanatrol or as rod says diedrich new masonry cleaner or NMD-80.