>Has anyone tried setting the enabled property on a form to false, and then setting it to true with something like CTL+'O'?

You could also try SETALL("enabled",.f.) to disable all the form's controls, but still keep the form active. A little difficult if you had some disabled controls before.

I would add a user defined SALESMANLOCK property of the form. Modify your controls base class refresh (you don't use the VFP classes do you?) to look for the SALESMANLOCK value. If it's .T. then save the current enabled property and disable itself. If it's .F. then restore the previous enabled state.
All you need to then is refresh and the controls know how to deal with it.

Not the best idea, because you will end up refreshing everything. Maybe using BINDEVENT() in VFP8 would be a better solution, so that you don't have code in the refresh method.