Aikido techniques flow one into the next. If someone knows an Aikido technique is coming, it will not be difficult for them to resist. However when you use the techniques together they will work nicely. A good technique to use along side kotegaeshi is rokyo. Here is an example of what I'm talking about
:
http://www.aikidostudent.com/oldasc/content/?p=301
Hope this is useful.