I'd brush before and after every wear especially along creases and feather. Dust and grit stuck in the creases is what cracks leather. I just put on a dab of bick4 on a rag and rub it in when leather feels a little dry. No experience with otter wax.
Damir Doma mainline
Lambskin - nubuck, dark grey
Made in Italy
Small dark stain near handpocket (see pics)
Rough measurements (no guarantees, fits me a slim 38 just fine):
699 + 15 shipped USPS