Verdigris will etch nickel silver (if it has not already) and will help rot leather. Bad stuff.

Getting it off without reducing oxidation (patina) is difficult. Maybe soap and water ?

Also, FYI, verdigris can be made to order by mashing Crayola crayons in an evaporative solvent. Sellers swear by it as proof that their piece has not been "messed with", but is not really true.

Advice: Take your lead from museums. They don't shine up their edged weapons, but they let them deteriorate either.