I do not use water, now. I use oil only with #2000, my last step before polishing cream compounds (for cars). I use sweet almond oil, just because I have it at home. It works well preventing rust (with water at #2000 after 30 mins I could see little yellow points appearing on the blade). After #2000+oil, I handsand with #2000+solid_soad, starting handsanding the soap (..not 30 mins! just few secs!!). This helps me to finish the work, since I can not find anything "smoother" thank #2000.