Vinegar and baking soda can effectively remove old carpet stains, and there are a few common methods for application. One method involves applying them separately: sprinkle baking soda over the stain, let it sit for 15 to 30 minutes, then vacuum it up. Afterward, blot the area with a solution of equal parts white vinegar and water. Another method combines the ingredients on the stain to create a foaming reaction that helps lift it. To do this, pour a generous layer of dry baking soda over the stain. Then, in a spray bottle, mix distilled white vinegar with warm water and a few drops of dish soap, and spray this solution over the baking soda. Let the mixture sit for several hours until dry, then wipe or vacuum up the residue and blot the area with a clean towel. You can repeat the process if the stain persists.

Eventually, vomit odors will go away on their own. However, it can take weeks for that to happen—unpleasant weeks. Using baking soda or commercially available carpet cleaner according to product directions will speed up the process. 

If your upholstery has a funky odor or you want to make your couch smell fresh, sprinkle some baking soda on the piece for 30 minutes up to an hour and then use the vacuum to remove the baking soda. If it’s still smelling funky, you may need to hire a professional cleaning service for a deeper clean.

DIY is possible for small or synthetic rugs. Professional services are recommended for delicate or antique rugs.