I'm not sure how effective it is but there is a product available that are treated paper strips that are suppose to slow the process down. But I think they still have to be changed every six months. So obviously you still have to have access to the piece. I believe its original purpose was to put in storage with your fine silver pieces.
Silver is especially vulnerable to sulfur compounds an keeping it away from these and
other oxidizing gases can help to preserve it.
Glass can function as a vapor barrier and if
it is used in counjunction with a completely
sealed package, tarnish can be minimized.
Instructions for making such packages can be found
at: pictureframingmagazine.com. There are scavengers like silver cloth that may be useful,
as would use of zeolite laden mat board, but
keeping harmful gases away is most important.