What to do with filler neck

I emailed Evaporust asking about it and here's the response I got:

The yellow residue is from Evapo-Rust reacting with the lead residue from when gas used to have lead in it. It gets impregnated in the metal. Acetic acid or vinegar will dissolve lead in the presence of oxygen. The residue that comes off will have lead in it and should be disposed of in a safe manner.

Makes sense I guess, although others here have said they didn't run into this on their filler necks. I don't want to soak it in vinegar because that will dissolve the plating on it. I think I will just leave it as is and run it.