IMO never never use any kind of acid diluted or not it will corrode & eat aluminum even if clear coated on AS. When we were racing motorcycles when piston seized in cyl. used to clean aluminum from pistons in cyl. also acid will destroy chrome on drains faucets etc. I will never let acid any where near my AS. I use a lot of acid but only in swim pool and clean rust from toilets drain cleaner etc. Premixed washes for aluminum will turn some aluminum wheels, fuel tanks etc. milky white, even black, it is tricky stuff. I use car wash w/wax mix and micro fiber mitt to wash AS, sometimes mild dish soap [dawn] spray bleach on algae rinse then good soapy wash. So as stated never use acid of any kind on AS. or any rough type of cloth or brush, also drop sponge can pick up grit again scratches. The first AS I pur. was
1963 that prev. owners pur new
1962. They washed with acid then used steel wool to mitigate damage, resulting a very scratched AS. I pur. very exc. price as would always be a scratched mess.