What is the recommended way of removing a siliconed in tub jet tube
That would not be silicone caulk. It is PVC glue. You can see the blue primer on part of the fitting. The PVC tubing would have been coated with PVC glue as would the interior of the fitting and the two of them twisted together. The tubing probably goes all the way into the fitting. It's almost impossible to get that apart without damaging it to the extent that you wouldn't be able to reglue it. When I've had repair jobs like that, I have replaced the fitting and added some extra PVC to connect to the PVC tubing.