I'm not sure what you mean by gaps. Is there any way to get and post a picture of this?

The advice about rubbing it with a bottle or jar is good but it works best after you have applied some conditioner. I'm partial to Lexol products (cleaner and conditioner) which can be obtained cheaply at most auto parts stores. While neatsfoot or mink oil work as well it's easier with them to get a little more than you really need on the strop.