Why do they ask you to take off all metal jewelry? Isn’t the metal within the body like having jewlery in your body?

The scalar field is unaffected by the metal, only the link cable and scalar unit can be affected by the metal. The metal within the body has no effect on the scalar field, it won’t interfer with the scalar field.

The jewelry is fine and it is ok to leave on during the treatment.

It does not affect the field, or the effect is so small to make it negligible.