Ave!
Just as a quick introduction, my name is Kevin Sandes and I know nothing about metal-detecting. But I do have close to 25 years of professional experience cleaning and restoring old/ancient coins and artifacts, from ancient Egyptian bronzes to 18th -19th Cent US coins, etc.
FYI - Del (Dan) asked me if I could share some of my thoughts in the cleaning forum and I'll do my best to advise those with cleaning/conservation questions.
Happy to be here!
Best regards,
Kevin