take the small line going to the TB from the coolant rail off and take the big line off the TB only and route that end onto the nipple where you took the small line off on the coolant rail. so youre just making the coolant flow in a circle through the tube. re-use one of the hose clamps from the small line to secure the big line back onto the coolant rail.
Don't waste your time. The coolant temp going into the throttle body will be cooler then the ambient temps around the upper motor and throttle body. Unless your car runs over 200º. Buy a laser temp pyrometer and prove it to yourself.