I'm trying to understand the reasoning for this. Are you dealing with very sensitive information that you have a real reason to fear the rubber-hose cryptanalysis method?
Although, honestly, the other part seems more bizarre. Gov't agencies and other clients are just giving you their sensitive passwords, and trusting you to delete them after the project, at your leisure? How is that not terrible security? Revoking a consultant's security needs to be in the hands of the employers.
But why even know your own passwords, what is the point? If I can double click from my manager and paste it into my password field and never have to worry about knowing anything, I'm much happier and safer.