##The Argument##

Whether or not salt water is clean or dirty is quite philosophical. Search freedictionary (not a great source, but a start) for "[clean water][1]" and it will redirect you to "drinking water." But most people are going to separate drinking water and clean water as two separate terms. 

##DM Says##

When it boils down to it, the answer is "ask the DM." If the DM allows it, then yes, if not, then no. You can try to argue it, but once the DM has ruled, that's it.

Since you are the DM, you get to decide really. To **you** is salt water clean? Oh and the spell only lasts for one hour, so sure, you can drink it and it won't be salty, but after an hour, it will be, and your character will get sick anyway.

  [1]: https://www.thefreedictionary.com/Clean+water