"Cha bu toil leam salann."
Translation:I would not like salt.
The meaning is somehow the same, but just as English I would like is more polite, the Gaelic cha bu toil leam… is also in a more polite conditional mood than simple I don’t want….
You’d need something else for simple I don’t want salt statement. Input from a native speaker would be better, but I guess you could use the verbal noun iarraidh: chan eil mi ag iarraidh salann (lit. I am not desiring salt) or maybe chan eil iarraidh agam air salann (?, lit. I have no desire for salt).