To scourge, simple means to whip...

Large metal whips with razors and spikes that dig into your flesh as your chained to the wall. Some with spiked balls at the end that break your fragile bones in the process, very much like there battle brother the Morning Star.

Those are more of the intense versions, but one of the most common was called the Cat O' Nine Tails. A Cat O' Nine tails usually did not have anything to do with nine tails, they usually had anywhere between 19 to 24. On these tails were large knots, metal barbs, and/or tied in pieces of bone to make the experiance all the more painful. An example of Cat O' Nine Tails is pictured above.