The List
There are 325 6 letter words with O as the last letter. The highest scoring is JAZZBO at 33 points in Scrabble. 244 carry three or more vowels, which makes them useful for dumping a vowel-clogged rack.
ABRAZOADAGIOADJIGOAERUGOAHCHOOAIKIDOAKIMBOALBEDOALBINOALBUGOALNICOAMMINOAMMONOANATTOANGICOAPOLLOARIOSOARISTOARROYOARSENOARSINOASIAGOAUSUBOAWHATOAWHETOBABACOBAGNIOBAGUIOBAMBOOBAROLOBARRIOBASUCOBAYAMOBEENTOBILLYOBISTROBLANCOBLOTTOBOLEROBONITOBONOBOBOOBOOBOOCOOBOOHOOBOOKOOBRASCOBRILLOBROCHOBRONCOBUMALOBURGOOCABRIOCALICOCALIGOCAMSHOCARDIOCASHOOCASINOCATALOCHARROCHEAPOCHEEROCHOCHOCHOCKOCHROMOCHURROCICEROCOGITOCOLUGOCOMEDOCOMODOCONCHOCOOCOOCOROZOCRAMBOCRYPTOCUATROCUCKOODAIMIODAIMYODAYGLODEXTRODINERODOMINODOODOODOPPIODORADODRONGODUELLODUETTODYNAMOEMBRYOENDUROENHALOENVIROERINGOERYNGOESCUDOFASCIOFIASCOFINITOFINSKOFOREDOFOREGOFORHOOFRANCOFRESCOFUGATOFUMADOGABBROGALAGOGAUCHOGAZABOGAZEBOGELATOGENTOOGHERAOGHETTOGIGOLOGINGKOGINKGOGITANOGIUSTOGOMBROGOMUTOGONGYOGOOROOGORGIOGREEBOGRINGOGROTTOGUANGOHAIRDOHALLOOHERETOHETEROHOLLOOHONCHOHOODOOHOOPOOHOOROOHULLOOHUPIROIGNAROIMBIZOINCAVOINDIGOJAZZBOJINGKOJOURNOKAKAPOKAKUROKAROROKARROOKATIPOKEKENOKIMONOKLEPTOKOKAKOKOODOOKOREROKOUSSOKWAITOLADINOLANUGOLATIGOLATINOLAVABOLEGATOLIBEROLIBIDOLIVEDOLOBOLOLOLIGOLUCUMOMACACOMADUROMAMAKOMANITOMANOAOMAOMAOMAREROMATICOMATIPOMEDICOMELANOMENUDOMERINOMIKADOMIOMBOMODULOMOJITOMOKOROMONOAOMOOLOOMORPHONANDOONARDOONIELLONONEGONOSTRONUNCIOOBENTOOCTAVOOLINGOOVERDOOVERGOPAKOKOPALOLOPANINOPARAMOPEDALOPEPINOPERNIOPEROXOPHYLLOPHYSIOPICAROPIOPIOPLONKOPOMATOPOMELOPONCHOPOTATOPRESTOPRONTOPSEUDOPSYCHOPUEBLOPUKEKOPUMELOPUNCTOQUANGOQUARTORABATORACINORANCHOREBATOREBOZOREECHOREGULOREZERORIALTORIGHTOROADEOROBALOROCOCOROMANOROTOLORUBATORUBIGOSAMFOOSANCHOSANPROSAPEGOSBIRROSCAMTOSCHIZOSCRUTOSHACKOSHEEPOSHIPPOSHIVOOSHYPOOSISSOOSKIDOOSLEAZOSMALTOSOLANOSOLITOSORGHOSPEEDOSPINTOSTALKOSTANZOSTATTOSTEREOSTINGOSTINKOSTUCCOSTUDIOSUBITOTAPALOTATTOOTECHNOTENUTOTERCIOTEREDOTHICKOTHUGGOTIFOSOTOLEDOTOMATOTOREROTRILLOTROPPOTUKTOOTUPELOTURACOTUXEDOULTIMOVAUDOOVELCROVIBRIOVIGOROVIRAGOVIRINOVOMITOVOODOOVORAGOVOSTROWANDOOWEIRDOWHACKOWHAMMOWHATSOWHIZZOWHOMSOWOOHOOZELOSOZOCALOZOOZOOZORINOZUFOLOZYDECO