Use as an anointing oil when you need protection from evil or spells. If you are astral travelling apply this oil to protect against spiritual attack and to protect your body.
Burning marshmallow cleanses an area of negativity. Use in transitional magics and place on the graves of the dead. 
Marsh mallow is also used for love and fertility spells. Sprinkle around the home to prevent infidelity. Wash the genitals with the herb to help fight infertility.