I use the Caswells at full strength. It gives a very nice finish. What I do is pour out a small amount of the Caswell's and take a artist brush and carefully brush it on the stainless. I do not dip my parts as I believe it just wastes the solution. It comes out extremely nice for me this way.

I prep by stripping any paint and clean it with Old Masters Finish stripper. Then I take OOOO steel wool and soak with the Old Masters and carefully clean the parts (cylinder, lock screw, gas plug). Then I warm the parts and brush on the finish. I use new clean rubber gloves to do that part so not to leave marks on the cylinder. It does come out very well for me as I have done about 4 this way.

I have never tried the carbon steel parts with the Caswells. I use a Brownell's solution that is kind of a light blue cream. I don't remember the exact name now. It is a steel blackener as well and works great on carbon steel. It does not look like a cold blue but more like black parkerizing.

That is just my experience for what its worth.