you want to delute the solids that remain of ther the grow and bloom cycles.
A good ppm meter will tell you what is going on.
I can no even want tothink of steaming them, 100 gallons of hydro corn.
I have used plain 3/8 pea gravel for years , the only reason I stopped using it was hydrocon is easer to clean.
NOTE you want to remove as much roots and stray plant mater before doing the cleaning porcess.
I have used hydrocorn/expanded clay and pea gravel over 10 years each and had no problems, so far.
A clean system is a happy system, happy stystem is a happy crop.
C croppers do it because it works , and are not in love with the plant.