Salt possibly used as a preservative (3)

I believe the answer is:

tar

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'salt' is the definition.
(both can informally mean a sailor)

I cannot understand how the rest of the clue works.

(Other definitions for tar that I've seen before include "It paves the way" , "Road-dressing for a sailor?" , "Hearty" , "used by those who pay to work on deck" , "one may need to pay on boat" .)

I've seen this clue in The Globe and Mail.

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