What's the difference between what you call a "tie-down" and what others call a "trial close?"
Anything?
I personally feel there can be a fine line between asking certain questions that are rhetorical and manipulative (for example: "You would like to know how to make more money in real estate, wouldn't you?") that can only be answered with a "yes" ... and a question that can be answered with either a "yes" or "no" that will allow the prospect to disqualify himself if he is not really a prospect for what you are offering.
I will always remember the post you made sometime back where you stated a good salesman is always asking qualifying questions where he is looking for a "no" respsonse. If the "no" response never comes, the deal is sealed by the prospect himself.