Re: Green stains on neck, how to remove?
you could try a spot treatment of wood bleach, but i really don't know how that is likely to affect the surrounding finish.
if it's really that much of an annoyance, the logical cure would be to remove any remnants of finish in the discoloured spot, as well as a little bit of the surrounding area, then and down to bare wood until you get past the stain, then re-finish/match the existing finish.
in other words: probably a huge pain in the ass that is more trouble than it's worth.
got a pic?