Share 'Blocking connection to Internet'

My school wants to add Kindles to the library but we need to not have them connect to unfiltered content on the internet.  According to a discussion answer from Oliver Chase,  there is supposed to be a way for them to disable the wireless connection/whispernet.  I really need to verify this before purchasing.  Has anyone else been able to do this?  I have spoken to so many people at Amazon and I…