5 letter words:
brook11,
robot7,
4 letter words:
boko10,
book10,
bork10,
kobo10,
koro8,
koto8,
rook8,
toko8,
took8,
boor6,
boot6,
bort6,
broo6,
root4,
roto4,
toro4,
3 letter words:
bok9,
kob9,
kor7,
rok7,
boo5,
bor5,
bot5,
bro5,
obo5,
orb5,
rob5,
oor3,
oot3,
ort3,
roo3,
rot3,
too3,
tor3,
2 letter words:
ko6,
bo4,
ob4,
oo2,
or2,
to2,