Train your users where it is and isn't safe to enter credentials.
How do you actually suggest this be done? Seriously? Classes? OK what's the estimated success rate of that class (i.e. how many people will go to the class, then ignore all the advice)? 80%? What do you do about the 20% who haven't been 'trained'? What next? Computer licences? How long will that take, and again, how many people will ignore it?
How do you actually suggest this be done? Seriously? Classes? OK what's the estimated success rate of that class (i.e. how many people will go to the class, then ignore all the advice)? 80%? What do you do about the 20% who haven't been 'trained'? What next? Computer licences? How long will that take, and again, how many people will ignore it?