How to disable specific apps using cellular data on iOS 6?

I don't have iOS 7 and I'm not planning to upgrade to it on my iPhone 4S. Is there a way to turn off data usage for specific apps?

Best luck.
http://lifehacker.com/...1463037304

http://www.cultofmac.com/253834/control-your-data-turn-off-cellular-for-certain-apps-ios-tips/

Just tell Siri "go to cellular settings", and turn that off

Can't do that under iOS 6.