CArtola,
Yes, soy bean oil is fine for the blend. In fact, one of the great things about this blend is that the the cheapest and most widely used vegetable oils found in restaurants is non hydrogenated soybean oil and thats what works best for this type of fuel.
Hydrogenated oils are more expensive for the food service operator to buy, though they get longer life out of their oil. As stated above, make sure you have a non hydrogenated oil. Clear Fry is a popular name for it. Then make sure you filter the oil. You can't filter it enough in my opinion.
Hope this helps,
Dale