This is a rather delicate subject, but if you didn't grow up with this tradition, you'll be glad you read this blog. It has to do with bathroom smells--poop. I know, I know, it's a delicate subject, but everyone had to deal with this sort of thing once in a while, so here we go.
I don't know anything about Northern grandmothers, but I'm an authority on Southern grandmothers, since I had two of them once, and I currently am one.
Southern grandmothers always kept wooden matches in the bathroom, not for lighting candles, but to use as a bathroom deodorizer. You can buy all the bathroom sprays you want to, but nothing kills bathroom smells like burning a simple wooden match. All you have to do is light it and burn it down about an inch, and you're done.
I looked it up on line and here's what I found: Burning matches don't actually do away with the order-causing gasses, but the sulphur dioxide that is produced when you light a WOODEN match, is more pungent than the bathroom gasses, so it achieves the same thing. One match/who knew.
Local grocery stores don't carry wooden matches much anymore, but hardware stores do. If you go on Amazon, however, you will find the kind of kitchen matches featured here for @$1, or you can buy the fancy little boxes of matches that I always take home from restaurants and weddings.