You can use bath salt instead of crude salt, but you can't use edible salt. Generally, big supermarkets are relatively thin.
Edible salt contains almost no nutrients except sodium. Bath salt is rich in beneficial trace elements such as iron, calcium, selenium, magnesium and potassium. High-quality bath salt is composed of natural sea salt, minerals and plant essential oil, which is non-irritating to the skin.
References:
Five bath slimming methods/posts/list /66 1.page