Yes Oatmeal soap is a good soap to clear up and help prevent acne.
I used to get a lot of acne outbreaks until I started using Oatmeal soap when a friend suggested it and now that I use Oatmeal soap to wash my face daily I haven't gotten anymore acne outbreaks.
The oatmeal soap absorbs the skins oils without drying it out.
I've also used apple cider vinegar with success before to get rid of acne.
Just soak a cotton ball in apple cider vinegar and apply the apple cider vinegar 2 times per day for up to 2 weeks and the acne should go away.
Lemon juice is another great way to get rid of acne and you just apply the lemon juice to the acne like you would with apple cider vinegar.