Depends on what you mean by "work". You steer with your elbows, which makes the bike much more twitchy. You also lose reaction time to grab brakes.
As far as "work" in the sense of speed....it depends on how flexible you are, and your bike fit. The more flexible you are, the lower and narrower you can get--the more aerodynamic you are....but the less (generally) comfortable you are. But you can go quicker for the same effort.
Getting them to "work" as in bike fit is tricky. You have to compromise between the bikes you have and how flexible you are.
Buy known vetted products like Profile Design etc. You have to have a well-engineered product. There are lots of knock-offs andfakes...yes you can roll the dice and buy El Cheapo off Ali, but you risk needing dentures if they break under load.