If your child has a wetting accident in their bed, or if you just want to freshen up your mattress use baking soda.
Apply a light dusting of baking soda on the mattress, you can also add it between the box spring and mattress. Then put the clean mattress pad and sheets on the bed.
The next time you change your sheets vacuum up the baking soda. You can sprinkle fresh on afterwards if you’d like.
You can also use this under couch/chair cushions.