it wont remove junk but it will keep it from sticking. The issue is that its always dry and then the oil vapor hits it and sticks to the walls You can clearly see on my pic that the oil formed a trail down to the valve. Cylinders 4-6 where not so bad and I can only put that down to the fact the injectors would trickle/leak and the gas vapor in the cylinders made it harder for the oil to stick to the walls or even eat the stuff from the walls of the inlets.
If you like customer service. Don't look beyond a BMW.