[xyzzyz]

As of now, the best that the researchers have achieved is 25% desalination

25% is quite far from "just fine". Has there been any progress on the method in last 4 years?

[amelius]

Repeat the process 10 times, and you're at 95% desalination.

[xyzzyz]

It may or may not work, depending on the details of the process. For instance, the process might only be able to separate the ions if the concentration is high enough. If it's the case, repeating the process on the result will not make any difference.