I got a part from someone else who applied a woodgrain appearence to the entire part. I have done lots of editing to the part itself, including deleting that woodgrain.
There are certain faces that it will always reapear on though. I have tried every way of deleting appearences that I could find to no avail.
My model is attached below, if you find a way to get rid of the appearences, try playing around with it a bit more, change lofts, sketches or whatever. It usually takes only a minute or two of playing around before the appearences reappear for me.