I would say it depends on where(which dam), when(season and time of day) and what(big or small) you want to catch. Most of the time it is better to go plain than use any flavours. The fact that you only caught one might be an indication that it was just a fluke. I see you are in the cape, so I can't really comment on venues etc. What you can do is go through some of the older post as there is a lot if posts on bait and dips. There is even a few pics showing bait presentations and explaining dips etc.Does dipping your bomb before a cast help?
I dipped one in curry powder and I caught a big one directly after, but im not sure if it had anything to do with the powder or if it was just a coincidence.