Green’s Dictionary of Slang

whip and lash n.

also whip and slash
[rhy. sl.]

a moustache.

[US]A.J. Pollock Und. Speaks.
[US]Maurer & Baker ‘“Aus.” Rhyming Argot’ in AS XIX:3 195/2: Whip and Slash or Lash. Mustache.
[SA]L.F. Freed Crime in S. Afr. 106: his ‘whip and lash’ [is] his moustache.
[UK]R. Puxley Cockney Rabbit.