Odorless mineral spirits is my first choice because it is cheap when purchased in large cans from the paint thinner section of your local hardware store and can be reused indefinitely to soak small parts in. Just like gunked up grease, the T-9 residue will likely need some scrubbing with an old tooth brush to get it all off. The stinky solvent fumes pretty much rise exponentially when using other paint thinners or de greasers so bear that in mind. Never gasoline.
Edit: If talking frame tubes, I have found that any automotive paste wax will dissolve the T-9 residue with some gentle massage but just watch out for grit on your paint/chrome.