Etching P.E for paint .
I saw the article about P.E. and Vinegar .As you know vinegar is caustic in and of itself .This is why it can work .Make sure the P.E to be soaked is spotlessly clean first .
I use another route here . I create a mixture of Comet cleanser and warm water .I drop in the clean P.E and swirl it in the mix gently .When I did the rails on the Wisconsin model for Nauticus and BaD shipmodels that's how I did them .
Promise not to laugh ? Another proven method is to lay your P.E in a shallow soap dish . Cover with warm water and use a Polident cleaning tablet .That works great as well . Make sure the tablet DOES NOT ! sit on the brass or steel . Tanker - Builder