A cat of nine tails is another name for the scourge! The scourge is used in witchcraft not as a punishment but as ritual cleanser! It is not exactly used to leave whelps (unless you want it too!).
Several religions actually use a scourge as part of their faith. Several devout priests scourge themselves as part of their penance to emulate the the flogging of Jesus Christ. The scourge is a harvesting tool used to thresh the ripe wheat to separate the germ from the hull. It was used by many slave owners to punish their slaves while in the fields.
In witchcraft it is a symbol of dominance and also of trust. It is used to show that you trust the other person enough to allow the to use it on you and not to hurt you because they are understanding that they get back what they give out. A very strong pagan belief! You have to understand that if you use it hard on the other person they can do the same to you. The scourge is one of the tools used during initiation on new coven members.
The scourge is in a sense a whip with several thongs instead of just one. Usually made of leather with knots on the ends. The scourge is believed to represent fire. Usually scourging is followed by the fivefold kiss.