Haven't been "gooi-ing" in years and haven't visited those places in recent years, but this time of the year we used to get them on the following and the most productive spot used to be about 15-20 left of the large Bloekom tree at the Old Northern Transvaal Grounds:
A small dough ("Deegie") covered hook with a small fluorescein backing dipped in the below or combinations thereof per hook and or both hooks dipped into one dip with another on the Mielie Bomb:
Tjop-Tjop (Pineapple flavour)
FX (Caramel flavour)
Banjo (Banana flavour)
Not sure if this still prevails, but it was the best stuff to use back then.