Green’s Dictionary of Slang

scour v.1

also scoure, scower, scowre
[SE scour, to rub]

[mid-15C–18C] to wear (fetters), thus to sit in the stocks; usu. in phr. below.

In phrases

scour the cramp-ring(s) (v.) (also scour queer cramp-rings) [cramp-rings n.]

[mid-16C–early 19C] to wear chains or fetters.

scour the darbies (v.) [darby n.2 (1)]

[late 17C–early 19C] to wear chains or handcuffs.