And you want to use this method to gauge a candidates communication skills? Human communication is a very complicated and error prone process. If you're going to cut out all the vital clues, how you can expect it not to fail horribly? Feedback from both sides is essential.
As you said it very well:
If you're going to cut out all the vital clues, how you can expect it not to fail horribly? Feedback from both sides is essential.
So by not offering the routine and quick forms of 'yes I understand', a good communicator will stop to see where the holdup is, a bad one will march on without noticing there was an issue.
When explaining things, I somewhat worry that I'm going to come off like an arrogant prick when I look someone in the eye and ask "Does that make sense?" If you don't, though, you run the risk of people not opening the floodgate of questions they have -- or, worse, you run the risk of assuming that they actually understand and that everything is golden.