I use Ballistol on my P01 (and everything else ) which also has the DW duty finish and no problems with discoloration. Looks as clean as ever. Love the smell of ballistol!
I have not used Ballistol, so I cannot comment on how well it works, or if it will damage the finish of your pistol. However, I do use Prolix. It cleans well, does not damage nickel, blued, stainless or Kimpro finishes. Prolix is said to be a lubricant as well as a cleaner, but frankly, I don't like it as a lubricant. You might want to contact DW and ask if Prolix would be an issue. I am betting it would not be. Just my opinion.