You probably won't be able to get all of the abrasive compound out of that strop, the general rule is that once a surface is pasted, there's no changing it.

But yes, more stropping is the key for me. I've never used pastes with any regularity and find that ~100 laps on a good leather strop smooth out any edge that is fine enough to be considered for a test shave.

A finer finishing stone couldn't hurt, but isn't at all necessary.