Anyone recommending baking soda on the face does not understand the pH scale.
Home skin care remedies can be great. I did a guest post on Holistically Haute about using sugar and olive oil on keratosis pilaris, and I will recommend (cooled) oatmeal paste for severely dry or irritated skin when a client can't afford a moisturizing mask. Home remedies definitely have their place!
Using baking soda as a scrub or cleanser is one of the most harmful home remedies that continues to be recommended despite the science proving it's terrible. "All natural and no chemicals!" is the most common tagline of people recommending its use. Baking soda is sodium bicarbonate, a chemical by definition: "Sodium bicarbonate is the chemical compound with the formula NaHCO₃" Everything is a chemical! Walnut shells, petroleum, and poison ivy are "natural" too, but that doesn't mean they are good for skin!
Healthy skin is acidic, falling between 4.5 and 5.5. Water is neutral at seven. Baking soda has a pH of nine.
The acid mantle of the skin protects it from bacteria, pollution, and damage. It keeps water from evaporating, keeping skin moisturized and healthy. Applying a very alkaline product to the skin completely destroys the acid mantle, stripping skin of every drop of oil and moisture and leaving it raw to the elements, allowing bacteria and pollution to damage skin, and making it much more sensitive to sun exposure. Chemical exfoliation is done with an acid, not a base.
Using baking soda on acne, when skin is already raw and angry, is counterproductive to healthy skin. Baking soda does have an antiseptic effect, killing bacteria, but since p acnes bacteria (the acne bacteria that lives on the bottom of the pore) is anaerobic, plain oxygen kills it without the skin sensitizing effect, and by simply unclogging the pores, oxygen can kill the bacteria. People that use baking soda do see a decrease in active pustules, making them believe that this method is effective and safe, but it's far more damaging than they realize.
Some beauty bloggers will recommend baking soda and lemon juice together to balance the pH, but unless you're a cosmetic chemist with strips of litmus paper handy to check your mixture, using proper skin care from a professional is far safer and more effective.
Instead of baking soda, try a kaolin and benzonite clay mask in the shower twice a week to remove excess oils and unclog pores. Make sure you're not using soap either!
Keep your box of baking soda in your kitchen or laundry room- not with your skin care.