It's weird this expression popped into my head. When I was growing up in the 60s and 70s, it was already fading from usage... But they still said it a little bit on TV...and on the playground...
I did not really realize that... I heard it on the playground and on TV. I thought it was more like saying, your mom is an unfeminine clod. It could reflect both ideas kinda rolled into one.
And Asbestos Mitts!