Protect your cabinet and floor surfaces with plastic drop cloths. Use painter's tape to secure plastic drop cloths to the underside of your countertop edge where it meets the cabinets. Lay plastic drop cloths on the floor as well.
Wear rubber gloves to protect your skin from irritation.
Remove existing stain, paint or varnish from your wooden countertop surface with an appropriate stripper. Apply the stripper to the wood with a paintbrush or rags, according to manufacturer's directions. Allow the stripper to sit on the wooden surface as long as is indicated on the directions; normally you will see the paint or stain bubble and soften on the surface within two to five minutes.
Wipe the old stain off with cleaning rags. Use a fine steel wool pad to remove stubborn spots of stain from the wood.
Wipe your wooden countertop with dry rags to remove all traces of the stripping agent. Dampen a cloth with warm water. Wash off the surface with the damp cloth, and then allow the wood to air dry overnight.
Sand the wooden surface to finish preparing it for whitewashing. Remove wood dust by wiping it off with a damp cloth.
Stir the whitewash stain with a paint stirrer before using it. Apply the whitewash stain directly to the wooden countertop using a clean rag or paintbrush. Cover the entire countertop or, for a larger countertop, whitewash one section at a time.
Allow the whitewash stain to sit on the wooden countertop for up to three minutes. Wipe it off with a clean, dry rag to remove excess whitewash stain.
Blend unevenly stained areas by applying more whitewash stain and blending it with a clean rag. Allow the whitewash stain to air dry for a minimum of three hours.
Seal the wood and protect the whitewash stain by painting on a polyurethane-based clear coat. Allow the clear coat to air dry for 24 hours before using your countertop.