"Can you"? Yes.
Would I? No, not unless you want to reduce your load by 10-15%, which puts your ball dangerously far down in the cylinder. Of course, you could use C.O.W. as a filler to bring the load level up, but that sounds like a huge PITA to me, personally.
Triple 7 in the small doses used in the pocket pistols won't create too much pressure or undue wear. When you move up to .36 or .44 then cutting back on the charge makes sense especially with a brass frame.
Let us know how it works if you try it. I have a brass frame CVA that I've only shot a couple cylinders thru. Hoping to get some trigger time soon; I have several new toys that need wrung out.