Is there something I can do with the extension tube (straw) so it doesn’t get lost?

The red cap on Chemtronics aerosol products like flux removers, degreasers, and Freeze-It Freeze Spray has a notch on the top. That is engineered for the straw to snap in and hold into place so you don’t loose it. The aerosol trigger sprayers that are common on dusters, freeze sprays, and flux removers, have two ways to store the straw when not in use. The hole at the back of the body of the sprayer is just the right size for the straw to slide into place for storage. The slot below the trigger is also the right size for the straw to snap into place, which also has the advantage of locking the trigger.