Of course, my stainless and nickle silver guns "show the dirt" more readily than my blued or matte ones
Right before I shoot any of my guns, I will go over the slide rails and the barrel hood (at a minimum) with FP-10-soaked q-tips, and I constantly wipe down the slides & frames with a silicone cloth, so there's no doubt that the "wet" gun (but not "drenched") is attracting more burnt powder residue, than if I shot them bone dry. However, the guns function 100% reliably, and are much easier to clean.