I too have always fancied tasting truffles, or buying a pig to find them for me to sell, (crazy money making scheme,)
(I get them when I really want something I can't afford.)
I never knew you could get them in any other form, interesting.
I once had a very odd slightly sweet smell that I had trouble locating once. It turned out to be an orange my son, or nephew, had left in a backpack in my son's wardrobe. It had gone mouldy and until the day I discovered it, I had never known they smelled like that.
Sorry, none of this helps you to deal with your truffle salt. Perhaps you could put it into another tin, wrap it in oilcloth, encase it in lead and bury it in your garden until you want to use it. lol :D