In a large bowl, combine 8 cups of water with 1 tablespoon of baking soda. Stir until the baking soda is fully dissolved. You can adjust the quantities depending on how many apples and grapes you're cleaning, maintaining the ratio of 1 tablespoon baking soda per 8 cups of water.

Place the apples and grapes into the baking soda water solution. Make sure the fruits are fully submerged in the water. You may need to do this in batches if your bowl isn't large enough.

Let the apples and grapes soak in the baking soda water for 15 minutes. During this time, the baking soda helps break down and remove the waxy coating and pesticide residues.

After soaking, you can gently scrub the apples with a soft brush to ensure the wax is fully removed. Grapes typically don’t require scrubbing due to their delicate skin, but you can lightly rub them with your hands if desired.

Drain the baking soda water and rinse the apples and grapes thoroughly under cool running water. Make sure to remove any baking soda residue.

Pat the apples and grapes dry with a clean towel, or let them air dry before eating or storing.