I have used TW-25B on the slide of my Sig pistols in the past. It works well but over time it tends to harden up. Now I use Slide Glide Lite on the rails and the outside of barrel. It works well and doesn't seem to harden. Over time it does seem to disappear. If I haven't shot a pistol in a while I prefer to check the rails to make sure there is enough lubrication still on the rails.
I know of several other Sig owners that use both of these products.