I am a bit late to this thread but I want to emphasize that the care of new leather that has been maintained and older, drier, historic leather is very different. That is why we may oil or polish our boots, shoes, and tack but generally don’t recommend the use of those products on museum collections. Solutions like using Renaissance Wax or sheep’s wool (where you are probably rubbing the wool’s lanolin into the surface of the leather) would also not be treatments I’d recommend without seeing the condition of the leather. Things like the CCI Notes and the National Park Service Conserve-O-Grams are conservative approaches recognizing that once substance are applied to leather they can’t be easily “removed”. So using things like the soot removal sponges where the surface is in good condition or a soft brush are treatments that are generally safe for most leather artifacts.
Red rot is a condition where the pH of the leather becomes acidic and results in the crumbly, orange-red appearance. Cellugel will not deter (or repel) this from happening as it is normally the result of the type of tanning process and exacerbated by poor storage conditions.