Combination stainless steel chain/ galvanized steel anchor
Tho’ Stainless Steel is not recommended for use in submerged anaerobic applications, I’ve successfully used it exactly as you contemplate. Over 10 years, my SS chain(s) did not suffer undue corrosion when heavily used with a (mild steel) “Delta” Anchor, nor with the (aluminum) “Fortress” anchor, both of which were also connected to Group 4 H.T. chains. (anchor -to- S/S -to- H.T. -to- Rope)
I’m not certain that you’ll appreciably reduce the chain friction (& piling), though.