REMOVING MUSTARD STAINS Dear Readers: With spring and summer approaching, it will soon be time for outdoor barbecues and parties. Hot dogs and hamburgers will surely be on menu. But the mustard that we love to slather on dogs and burgers may also drip and end up on our clothing. If this happens, try to remove it as soon as you can. Dampen the areas and rub liquid laundry detergent into the stain. Rinse, then soak in laundry detergent and hot or warm water for several hours. It will be gone, and then you can launder it with enzyme detergent. — Heloise INSTALL A PUMP TO SAVE WATER Dear Heloise:…