Afraid I'm with TJ on this, salt baths are something that we used to advise with no evidence to support it's use or effectiveness.
Loads of trials have been done and have shown no improvements to healing times.
When our youngest had an op we were advised to salt bath the wound, asked the nurse why the ward were advocating this when evidence showed it did not work. She said that it was mainly for the benefit of the parents, would give them something to do to feel they were helping and involved in the process.
Asked the SHO on the ward and he said the Consultant was old school and stuck in his ways, and it would likely do no harm.
However, go for it if you want, you'll be fine.