Maybe I'm missing something but my understanding was that they would have spent that time:
1. Fighting the Unmade who don't seem to be sent back to Braize like the fused. In one of Dalinar's visions they fight the midnight essence between desolations. So, during this period that was basically a long in-between period they fought the unmade just like before. So, in my mind this would be the period when they trapped ReShephir (spelling?) in the tower, and possibly other unmade were similarly trapped or defeated.
2. Fighting the leftovers of the parshendi and the men who followed Odium, we know for sure that some of the parshendi/listeners did survive and others were enslaved, perhaps it was partially the realization that the parshendi were people and didn't deserve to be fought/hunted that (combined with the realization that they were the original inhabitants of Roshar) made the knights abandon their oaths.