Keeping the tube sanitary after use?

Is washing the tube in soapy water and letting it air dry after use good enough to keep it sanitary or a spray of Clorox wouldn’t hurt?

Soap and water is fine. If you use a water based lube like KY jelly or the cheaper Target brand equivalent, you don’t even need soap. I do stuff a hand towel inside mine to dry it right off though, and then you won’t have any water spots! Forget the Clorox.