Yeah, pretty much anything more complicated than a solid piece of metal such as a socket or an extension from Harbor Freight is roughly equivalent to a giant "kick me in the nuts" sign on yer groin.
The biggest POS ---- a Harbor Fright hydraulic press. I used it a couple of times and it literally blew a seal, spewing staaaaanky hyd. oil all over my shop floor. Whatever they use in it doesn't smell like "normal" hyd. oil.... something like a cross between moldy sox and rancid butter.
Bike related... probably cheap gloves. The most memorable ones were the blue/white Olympia ones that I had to buy at the track because I FORGOT my nice Held gloves. Instantly down-graded them to street use, and every time my hands sweated, they turned blue. I gave them away.