If you are cleaning your teeth with salt and bicarbonate, you are using an abrasive, and this will wear away the enamel on your teeth, regardless of what abrasive is used.
Oil pulling is a better option if you already have enamel loss.
Silica and magnesium supplements will help remineralise teeth, this is done from the inside out, not from the outside in. Silica will also help with gum health, bones, nails, skin and hair.