Should you hose down your bicycle after having used it on salty roads?
Here's how I understand the situation generating the question:

While riding to work on a salty wet road the drive train has become a salt water saturated mess. Now you are at work and have access to clean water but no ability to clean and lubricate the drive train.  

If that's the case...
Running some clean water over the drive train to wash off the salt water so that it does not sit on the drive train all day makes sense.
Clean water is better than salt water.
Clean water and then drying the drive train is better yet.

From an article on the effects of saltwater on metals  


  The combination of moisture, oxygen and salt, especially sodium chloride, damages metal worse than rust does. This combination corrodes, or eats away at, the metal, weakening it and causing it to fall apart. Saltwater corrodes metal five times faster than fresh water does
  sciencing.com


Both salt water and fresh water corrode metal. Salt water corrodes faster so drying the drive train helps.
Once you get home it would be best to clean and lubricate.