1) In the earliest contexts ‘ooze’ meant juice, sap; the liquid obtained from a plant, fruit or the like, and a fifteenth-century reference described squeezing the ‘wose’ out from grapes (OED). It is distinct from ‘ooze’ in the sense of mud but the meanings of the two words overlapped from the sixteenth century when the tannin liquor in which the hides were steeped was called ooze, probably ground oak bark in water.
Distinctive spellings had initial ‘w’: in 1673 a Selby tanner had 1 back in lime, 12s: 6 hides in wouse, Ł3 1 8. The spelling had changed by the early 1700s: 1707 Sixteen Hydes and six Necks lately in the Lime and now in the Owse, Frizinghall. In the inventory of Benjamin Empson of Sandal, an early eighteenth-century tanner, are nine references to Ouse Pitts, e.g. Item In Other Ouse Pitt twelve Bend Leather Hides.