Live or online, I think you should only do it willingly to serve a distinct purpose (tilt a guy by showing a bluff). IOW, hardly ever. I never do. Tilting someone in an MTT for example, can seriously backfire on you. I think it has more success in cash games, maybe.
I almost never do it as any suave player can really use it to gain valuable insight into your game play. Still, I see some players make the following mistake; they call every street and then fold. Then they feel silly for doing so and they show the laydown they just made.
Critical error, if you ask me. Especially if you just showed that you will fold a big hand - this really says "go ahead and bluff me on dangerous boards, I'll let you!" Yet, they just cannot stand being thought of as a weak player...guess what? That is a tell as well! Says you care as much or more about what other players think of your play than the hand you are in or if you can beat them, frankly (You are a vanity player who fears risking the hero calls). Amazing what you can pick up isn't it?
As for misdirection, well, I think it's like using a baseball bat to swat a fly in an MTT; weaker players might fall for it, but do you think if they are weak already they will understand? No. And better players know what you are doing and can still use it against you. Deliberate misdirection is also a tell; says you think you are a smart player and enjoy deploying a fancy strategy now for use later. The better player will just wait for an opportunity to allow you to do so and you will fancy play yourself right over to the rail.