Salt bath for purification

Hello

I was advised to have a salt bath for purification and to get rid of the negative energy. I ordered Himalayan salt but I got refined salt instead😞. So will it have the effect or I should get Himalayan salt?

Besides I wanted to put some salt beside my door entrance to block negative energy but I am afraid normal salt wont work.

Lastly what quantity of salt should I put and does it have to be in an opened container?