One not drinking alcohol, tiniest amount of Cinzano spat out by duck? (6)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

1st letter of ( tiniest amount of ) “ Cinzano ” deleted from ( spat out by ) “quacker”(slang for something that quacks, eg/? a duck). Answer: A member of the Christian group, the Religious of Society of Friends, which advocates not drinking alcohol (or drinking in moderation).