You mean like magical salt water?
It would have to be some damned salty water. Also there are problems with how would it condense out of the thin martian atmosphere and remain salty.
We’ve pretty much determined that there is water in the martian environment but when it contacts the atmosphere it “boils” off almost immediately due to the very low pressure.
I’m more inclined to think that what we see are clumps of dust drawn together by static.