Black soap and salicylic acid are both really good for blackheads. I recommend the black soap from Ghana (on Amazon).
The only SA treatment I recommend is Lumiplexion. Store brand SA is not strong enough. Her website is www Lumiplexion .com (spaced out intentionally so it's not spammed) Go to products, then prevent breakouts. You will see the salicylic acid. You would use strength 1. Once you've gone through a bottle of #1, your skin will be ready for #2. Excellent for both the blackheads and the little bumps that are under the skin. A bottle will last you about three or four months. She also guarantees her products. She has a promo code this month of "TimesAreChanging" - if you spend $85, you will get free shipping with that code. Normally free shipping after $125.
Good luck!
Julie