Usage: 3 forms in 3 verses
Form Translated As     In Verse(s)
αποκαθαρθέν being cleared away LXX.Job.7.9
αποκαθαίρονται clear away LXX.Prov.15.27
αποκαθάρωμαι should clear away LXX.Job.9.30

Liddell-Scott-Jones

ἀποκαθαίρω (apokathairō) to clear away G:V

ἀποκαθαίρω,

aorist infinitive -ῆραι[Refs 2nd c.AD+], but subjunctive -άρῃ[Refs 4th c.BC+]:—clear, cleanse or clean quite, . τὴν χεῖρα εἰς τὰ χειρόμακτρα upon the towels, [Refs 5th c.BC+]; τοῖς προσθίοις . σκέλεσιν, of flies, [Refs 4th c.BC+]:—passive, [Refs]:—middle, rid oneself of, [Refs]

__2 refine metal by smelting, [Refs 1st c.BC+]purified, [Refs 1st c.AD+] to be pure in dialect, [Refs 2nd c.AD+]
__II cleanse off, clear away, τὰς τραπέζας[Refs 5th c.BC+]; remove by purging or clearing, ἴκτερον[Refs 1st c.AD+]; .ἄνω purge by emetics, [Refs 5th c.BC+]:—passive, to be removed by purging, [Refs]: generally, to be got rid of, [Refs 5th c.BC+]; to be thrown off, [Refs] —middle, ἀποκαθήρασθαί τι get rid of a thing, [Refs 5th c.BC+]rid oneself of.., [Refs 5th c.BC+]