soft paper loans

I am a newbie investor, and have read about using soft paper notes to buy a property. Does anyone have experience with this, especially in the state of Illinois or South Carolina (2 areas I am interested in investing). Does the owner of the house not want to go through the same “pre- approval” process as a bank? How is this mortgage recorded, I am assuming it does not show on your credit. My credit is good, however finding the first property to break even on (through renting) is difficult through traditional financing.
I would also think that most owners would not be favorable to this (owners of personal residences trying to sell).