Implementing GTD in a company

[clango]

or sending @WaitingOn reminder emails regularly every Monday to people you're waiting on something from, or designating a public Inbox for others to drop notes/memos into.)

1. sending @WaitingOn reminder emails regularly
2. designating pubic inbox for others

Is it a frequent technique? Successful?

and could you please describe more in deep what do you mean for a public inbox for others? I cannot yet visualize it!