I maybe too late to tell you, just return for exchange. I have 20 years experience in optics and semiconductor. To wet cleaning at this early stage, you just make Nikon very happy because you are not only void the warranty but have good chance make the "greasy stuff" dragging around all over the sensor. I used to work in a military optical shop. Cleaning the lens, prism, reticle is not an easy task leaving alone the 5-microns size pixel on the CMOS sensor. Save the trouble for yourself. It's Nikon's job to figure out where the internal debris came from. An average consumer always makes a mistake thinking he is better than the professionals. That's why there are so many posts teaching you to be a Mr. Cleaner. This job is not for a two-weeks-old camera.