I'd like to update what I did here. I decided to try the Neatsfoot Oil on top of the black rocks. I decided I could always re-bath if it didn't work. I actually heated the oil a little and applied with my bare hands, rubbing it in well. After the first complete treatment I used my blow dryer to warm the leather, then buffed it. I applied a second complete coat of oil (with my fingers) and rubbed it in well. I buffed the bag with a soft cloth and it's already much softer. I will see if it needs more tomorrow or maybe a final touch up with black rocks but so far the difference is amazing!
I have used Neatsfoot Oil a lot in years past when I was tanning hides. I wondered if it would work on expensive handbags but was afraid to try it. I was going to order Leather Therapy or Leather CPR when I noticed some products actually contain Neatsfoot Oil. I always use pure and never the compound as it's mixed with other things. Neatsfoot oil is made from the hooves of cattle so what better product to use on cowhide? And the great thing - it's cheap.
Amazon has 32 oz of pure Neatsfoot oil for only $8.49 + $4.13 shipping but one can always buy a smaller container to see if it works for you. Hope is helps if someone wants to try it.