Glad its working again.
However, in my experience cleaning mice, you have probably only cleaned it just enough to get it working again for now, and it will stop again soon. You really have to open it and do a thorough job as described in NormConquest's post. Of course, be careful not to break the ring trying to remove it. If you just can't get that ring off, you can remove the screws on the bottom holding the case together. You don't have to worry about having a pile of keys fall out!