It seems pretty popular. Couldn't hurt to try. There are TONS of apps to do this with on the app store. I use Google's Hangouts and just archive the chats I don't want to see, but it does show them again if you are messaged again.
I use Vault. You can hide SMS and pics. Pretty cool app and it's free as well. This other mentioned above isn't compatible to my device for some reason.
Well, I use the the 360 Antivirus app locker feature to lock down the messages abut if you are talking about particular message locker then I would say you can try using the File Hider, (On PlayStore it will be available like a music icon, i.e. its Camouflage of the application ). It works well, and unknown people will never know what's this application is all about !