This worried me half to death I had lied to a teacher and now the whole class had just lied to God. I believed in God and burning in hell in those days, I couldn`t concentrate or worry and in end, the truth came out.
The teacher was understandably furious, I had to stand in front of the class while she shouted at me, then whacked first with one hand and then the other with a ruler. Now I had had the ruler rapped across my hand and leg before for incomplete work, too many mistakes, low marks in a test, etc but this was something very different. She really thrashed my hands, entirely deserved I have to say! I got the slipper for a couple of silly bits of behaviour but those occasions were not as painful as that ruler.
So sorry I cannot give a comparison between the cane and slipper at the primary level, but between ruler and slipper, my vote must go to the ruler!