How to Remove Mustard Stains
Mustard powder can be brushed off. Prepared mustard produces a stain that is difficult to remove.
On Washable Fabrics
Rub fresh stains between your fingers in a mild detergent solution, then sponge with an ammonia solution. Soften dried stains at first with a glycerin solution, and let stand for at least an hour.
On Other Surfaces
Sponge carpets and furniture with a mild detergent solution, then an ammonia solution. Avoid over wetting, and finish by sponging with clean water. Stubborn stains require professional cleaning.