Ankle warmers come to mind. Inversion boots (though they did make an appearance in Back to the Future II), topsy turvy tomato planters, togomatchi? electronic pets. Most things from Ronco (fill your own squeeze tubes, pocket fisherman, Popeet collapsible containers). Most anti-snoring devices. Anti-balding products up to and including Minoxidil. I'm sure there are a multitude of medical fad products out there from the 1930's through the 1950's as well.
