FYI I did manage to do it a hacky way by adding a trigger to run on disconnect (Session.SessionType = 'Access' AND Event.EventType = 'Disconnected' AND Connection.ProcessType = 'Host') to run a batch script from the toolbox with just this in it "echo off | clip"

Doesn't always work, sometimes puts up a run prompt after you have logged out. Probably also the client would see a black command prompt window for a split second as you log out.
I did look at trying to add it to the script that is part of the 'Selective Lock on Disconnect' extension, but there was protection to stop you from adding commands into it, and anyway it has to run in the user context and not sure that one does.

I would definitely enable a feature to clear the clipbaord and all history from every machine as we log out if we could. The clipboard is a temporary spot and clearing it would be a rare minor issue to any of our clients in my view, very few would be actually using history. But security wise it is a big problem. We now have disabled by default the share clipboard, and will leave it as such but often enable it and it would be easy for my techs to enable it to copy a file over then later copy a admin password without thinking about it. I see no reason why clearing the clipboard and history on disconnect couldn't be an optional feature that partners could choose to use.

Please please please add this feature, surely it is very easy to add and it would be so useful. 

Can this PLEASE be looked at?
All I want is a shortcut key to paste in - hundreds of times a day we log into a server and paste in the password from our password manager.

Have been checking on this request for a while so thought I should add to it. We do the send clipboard most times we connect to a server and it would be so much easier to have a shortcut key for it. CTRL+ALT+V would make most sense to me but anything will do really.