Finish Flesh Side of Belts

[treq10]

I'm making belts with W&C English Bridle. The flesh side is already very smooth, but I have noticed that over time it can start to come loose. Is there any way to finish these in such a way that the flesh side will remain intact over long periods of time (years even?) 

I have seen Ian Atkinson use Tan-Kote to finish the flesh sides. What does this do? Is this recommended here or are there better methods?

Lastly, should the flesh side finishing be different on tooling/veg-tan leather vs. a finished leather like English Bridle or Traditional harness? 

 

Thank you so much for your help!

-Dave