I think Susan makes a valid point. It doesn't invalidate the idea, but it does point out that, as with so many other things where the devil is in the details, you have to be selective as to where and with whom you store things. There are households where you can safely store a sealed bucket or three with and there are those which, live as grifters, are near the ragged edge of destitution, or have kids likely to get into everything, where reserves carefully socked away are unlikely to be there when needed.

Some of this is just knowing and knowing how to read people. Some of this might be controlled through packaging and placement. A package stuffed into the far reaches of a basement, attic, or crawlspace is less likely to get messed with than one in a well traveled area. A nondescript container that neither catches the eye, nor suggests anything interesting might help. Beware OD green containers because little boys all know that is where you find bayonets and war stuff that is fun to play with. Avoid orange and red, and any markings that indicate emergency use for much the same reason.

I don't know as I would go so far as to advocate stuffing your buckets in simple brown cardboard boxes and marking them as Christmas decorations, or something else unlikely to inflame passions, but it is a thought. You certainly don't want to get too cagey and deceptive about it because you will want to be able to find it when needed.

An acquaintance had a set of modernist end tables on either side of his couch. These were cubes, about 24" on a side, made of plywood and painted matte black. This was a pretty common motif in the late 70s. These were entirely featureless in normal use and I doubt anyone gave them a second look. If you flipped them upside-down and removed four screws they were hollow and perfect for storage. He never kept anything inside but was aware he could.

A lot depends on the household.