Never tried WD-40, but I have used Ivory soap and I know a few racers that would use Pledge.
From my experience with cleaners/solvents, the most common mistake people make if they use them is that they do not allow adequate drying time before waxing, and then they do not prep wax their skis, but instead only apply on quick/thin layer of their final wax. Similarly, when people hot scrape, the most common thing I've seen is people overheating the base or core. I've witnesed some people going so far as heating the core so much that the topsheet was HOT to the touch, I'd guess well over 100 degrees. I still recall learning to tune and being told, as soon as you can feel any warming in the topsheet, let the ski cool (afterall it is heat and presure that cure the adhesives in between the sandwich construction layers - therefore, heat and lack of pressure can affect the adhesion between the layers as well).