oh and as for decanters, lead free glass may be okay, however that depends entirely on how much lead is in the glass, and it can still fuck with flavor. the best would be something like borosilicate which is laboratory glass, aka pyrex. or quartz crystal. both are used for the consumption of medical weed, and obviously non medical however quartz is used because it doesnt leech anything bad for you specifically because quartz is used for blow torching and then vaporizing hash oils off of, meaning at room temp its even more stable and wont leech. search dabs or bho or hashoil dabs on youtube if you are curious about the vaporization thing, and quartz bangers or nails are what the piece that gets blow torched is called. quartz can also be worked like glass just needs a higher temperature however glass artists around the world are doing bongs pipes and nails/bangers out of it and borosilicate and other artwork, so finding someone making a decanter or some sort of bottle shouldnt be hard and if not a glass blower making these items would easily be able to make you a decanter and have a ground airtight top, or a flame polished air tight top if you prefer. plus going that route also means one off decanter, though it will cost more it would be a one off and colors can be done so help preserve the whiskey or working done to put designs on the bottle.