Jumping…have no hesitation to really get in there, its a waterproof/swimming band. I just got my second used one in and soaked it for hours on end in dish soap water. Take a toothbrush to it with medium force along the grain of the fibers for visible soiling. Be wary of any frayed ends as you don’t want to lift them up off the band further. I took some cuticle scissors to my Kraft/Lime and cleaned up some of that as well.
Leather you do want to be very careful. Prevention is the best medicine. Don’t wear it for too long, keep it dry, yadda yadda.
My improvised method for cleaning Swift or Gala leather (Barenia turns moisture into patina!) is to wet one side of a cotton swab for a controlled bit of moisture to lift dirt, and then quickly use the dry side of the swab to mop up the moisture. The stem of the swab gives you a decent amount of force to apply, I think.
But leather damage/aging is pretty permanent at the end of the day. Definitely a nice feature of the old Epsom bands, they’re pretty impervious to stains and clean well and can stand a little more moisture in the cleaning process. Though the edges are like any other band and will get permanent damage.
Another conversation is conditioners. I don’t know that the Swift leather would really benefit from it. Certainly Gala is pre-waxed and doesn’t need it. Early in all of this I did receive a mint Barenia Rallye, got one drop of water on it, didn’t realize it would fall through the “window” of the leather and begin the patina process.
So I freaked out and doused the whole thing in coconut oil (which i was doing with my Leather Loops back then because they were so damn creaky and we know how those edges age) and darkened it. I think it looks better than the really bleachy new-fauve-Barenia look and I feel like i stupidly backed into the right move, as it has an even “tan” instead of slowly watching random pits of patina build up across the band?