This video shows a quick and easy way to make a carpet spot remover using vinegar and baking soda. I've got to say I've always been impressed with how well vinegar and baking soda clean just about everything. Not only is it safe to clean with these two ingredients but it's effective at removing heavy soil.
I clean carpets professionally in Tampa FL and I have used a lot of different carpet cleaning products but I recommend this DYI carpet spot remover more than any other. Although, my version is tweaked a little to reduce the over powering vinegar smell while still remaining effective enough to take on tough carpet spots.
When applying this method to remove carpet spots apply the baking soda to the spot first and let it sit there for about 20 minutes. Try to distribute it evenly across the carpet. A mesh strainer or a flour mill could be used to shake out the baking soda for better coverage. After 20 minutes gently brush the baking soda into the carpet. You can do this with a soft bristle brush, a towel, or your hand.
Before spraying on the vinegar mix it with water at a 1:1 ratio. If your really want to up the cleaning power mix the vinegar with some soda water instead. Now spray the vinegar solution onto the carpet spot and let it sit for about 30 seconds to a minute. It's always fun to watch it bubble in the carpet. The last step is to towel dry the area to remove the carpet spot. Remember to blot the area dry don't rub it, you can damage the carpet fibers. This is a great carpet spot remover, so give it a try.