This doesn't answer your question. But:
Your feet shouldn't rub against the skate below the ankle. Something doesn't fit right.
If the rub is along the whole top sides of the boot, where your ankles slide forward because you prefer a boot fit that lets you slide them (instead of bending the boot) to accommodate bending your ankle, you could use gel inserts (like Silipose pads) so your skin doesn't rub.
Nor should there be a single point where your feet hit your boot. Again, misfit.
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Leather is just preserved (poisoned) and oiled animal skin, usually cowhide. Cleaning it isn't black magic, and doesn't require special leather-specific chemicals. A damp cloth, maybe with baking soda, should work fine, as long as you let the boots dry well afterwards. But avoid soap and other detergents if you can - it might break up the oil droplets that lubricate the leather, and the leather could crack.
I'm not sure if this will help, but if you have a lot of sweat, it's possible you need to renew the oil a little. If the insides aren't suede, you could occasionally oil the leather on the inside, using Neat's foot oil (use Lexol brand leather conditioner instead if discoloring the leather bothers you). Suede needs different cleaners, because ordinary oil destroys the nap.
Some people who's feet sweat a lot say it helps to use antiperspirants on their feet. I can't speak from personal experience.
If you think the leather could be rotting or molding, let them dry out better after you skate, and store them in drier conditions.
Insoles are easily replaced, if that is where the problem is. Buy cheap insoles at a dollar store, trace the originals (which you keep for future reference) on them, cut them to shape, and add tape or adhesive foam underneath to shape them vertically to fit your feet. That's $1 or $2, so it's no big deal.
I've used Febreeze [sp?] and similar products for odor. Again, leather isn't black magic that requires special chemicals.
Needless to say, if you skate without socks, socks would help. But that's your choice.