Usually I ran the script for 6-10 hours a day during the week (more intense on weekends), and used 3 hour intervals with one hour breaks while changing it quite often. I also used break days, where I did not log on at all as fishing minnows can seem very click intensive. This script got me from 92-99 in two weeks with no ban. I also changed up my methods (barbarian fishing, monks, and then went back to minnows) through sampling his other script, check it out here, which is also flawless.
Cheers.