Is this old-school or what?

Or maybe a little half-a$$ed???

I found a book at the local library on homebrewing wine and beer. It was interesting to read, keeping mind it was printed in the 70's. Anyways, although airlocks existed then, they recommended using mason jars if a homebrewer did not have access to airlocks. Simply put the lid on upside down and leave the ring somewhat loose. Inside air could excape but outside air could not get in. Seems like it would work in a pinch but with airlocks being less that $2/pc. someone would have to be hard up.

has anyone else heard of this?

I've heard of people simply laying a towel over a bucket...

I use cheesecloth during fermentation for winemaking.

You wouldn't believe some of the stuff I had to live without when I started brewing in 1989. I remember having airlocks, but I must have done 200 batches without a bottling wand/spigot, just holding my thumb over the hose while I switched bottles. Didn't have a lever capper either- just this really archaic one that you put on top of the bottle and hit with a hammer.

I have heard of using a balloon with a hole in it as an airlock. CO2 is only able to escape when the pressure builds up.