Removal of vomit stains depends on where the stain is located. In fabric, scrape off excess vomit, pretreat the fabric with prewash stain remover, and wash the fabric in the hottest water safe for the fabric. For upholstery, use a clean white cloth with dry-cleaning solvent to sponge the stain, and repeat until the stain disappears.
If the stain is located on a carpet, scrape off the excess vomit and sprinkle baking soda, cornstarch, or another absorbent on the stain. Let it stand for 10 to 15 minutes, and then vacuum. Then use a clean white cloth and sponge the stain with a dry-cleaning solvent. Blot the stain until the solvent is absorbed. If the stain remains, use one tablespoon of liquid hand dishwashing detergent and one tablespoon of white vinegar with two cups of warm water. Sponge the stain with this solution until the liquid is absorbed. Then, sponge the area with cold water and blot dry to remove the detergent solution.
As an alternative method for clothing, put the garment in a large bowl and apply a bit of cold water directly onto the stain. Apply baking soda to the stain, completely covering it. Pour lemon juice over the stain until it starts to fizz. Once it begins to fizz, rub the stain vigorously with a cloth or brush. Rinse the stain with cold water, and pour a generous amount of dish detergent directly onto the stain. Then, soak the garment in cold water for 30 minutes. Wring out the garment to remove excess water.