Make a thick paste of baking soda and water.
Apply a thick layer over the stain, let it dry for an hour, then vacuum.
For Stubborn Stains

Sprinkle baking soda over the stain.
Spray white vinegar using a spray bottle.
Allow the bubbling reaction to occur, let it dry, then vacuum.
For Odors

Sprinkle a layer of baking soda all over the mattress.
Leave for a few hours, then vacuum.
4 – CLEANING A MATTRESS WITH DISHWASHING LIQUID

Instructions

Mix 3 tablespoons of dishwashing liquid in 1 liter of hot water until homogeneous.
Application

Soak a sponge or washcloth in the mixture, wring thoroughly, and rub the mattress, covering all areas.
Rinse with a washcloth in clean water.
Press towels to absorb moisture and let air dry.