When I did use some TruOil (and I haven't since the 70's!) I tried the marbles in the container trick to keep it from going to waste.
I still have a container on the shelf of hardened TruOil complete with decorative marbles cast into place inside the compound & jar. It's just for lookin',,as they say.
My Permalyn finish did the same more recently. First time I used the stuff and didn't think about it going bad. The finish itself rather quickly,,the sealer didn't turn for almost a year.
I'll go back to putting it up into small prescription bottles again like I used to do with other finishes.
That worked well, air tight & most of us at this age have more than a few of those containers around.
Maybe I'll carve my precious cats-eye marbles out of the fossilized Tru-oil and use them for spacer in the med bottles.
Though the use of some clean cheap bolts/screws/nuts or pebbles is a good one.