Scrape off tomato sauce residue from the napkins using a spoon.
Lay the white table napkins flat with the stains facing up. Cover the tomato sauce stains with talcum powder to absorb the grease. Leave the powder on the surface for 15 minutes before brushing it off.
Mix 1 teaspoon of laundry detergent and 1 gallon of warm water in a bucket. Place the white table napkins in the bucket and allow them to soak for 30 minutes to loosen the stains.
Remove the napkins from the bucket and wring them out. Wet a clean sponge with full-strength white vinegar. Dab the remaining tomato stains with the vinegar to remove the discoloration and grease.
Apply stain remover solution to the napkins and allow it to soak into the tomato sauce stains for one to two minutes.
Wash the white table napkins in warm water, adding laundry detergent to the wash cycle. Repeat these steps to remove any remaining stains before drying the napkins.