Stronger rubber cement?

A useful tip for storing cans or bottles of such materials (including
paints, as well) is to store them upside down.
That way, any slight imperfection in the seal around the lid will fill
with the glue, paint, or whatever, and dry to form a perfect seal,
which will preserve the contents.
If you store it right side up, only the vapour will be seeping out of
any imperfections, and the contents will dry out.
The only downside is that it can get difficult to open, if the seal
was particularly bad to start with, as the glue or paint will stick
the lid on rather firmly. But that only happens in the case of a
container in which the contents would have dried out anyway, so you
haven't lost anything.

That sounds good.
But it doesn't explain the pail of water.