More particularly, the invention resides in a process for the production of an organo-aluminum-silicon reducing agent consisting essentially of reacting a hydrogenpolysiloxane having a viscosity of from 5 to 100 cSt at 25??? C. and siloxane units having the formula: ##STR5## wherein R is a member selected from the group consisting of alkyl having from 1 to 6 carbon atoms, cycloalkyl having from 5