Salt is a strong Antibiotic and I have known of people who expelled worms using high doses of salt. But my suspicion may be due to its electrolyte capacity. Sodium (salt) is antagonistic to both potassium and magnesium, it is quite possible that you are deficient in potassium/magnesium and the excess sodium is causing problems. I would both increase dietary intake of these two and consider taking supplemental forms and see if this resolves the issue.
I would use a high quality mag supp like UltraMag.