4 letter words:
bows9,
cows9,
scow9,
swob9,
cobs8,
woos7,
bios6,
bois6,
boos6,
coos6,
obis6,
obos6,
3 letter words:
bow8,
cow8,
cob7,
sow6,
wis6,
woo6,
wos6,
bio5,
bis5,
boi5,
boo5,
bos5,
cis5,
coo5,
cos5,
obi5,
obo5,
obs5,
sib5,
sic5,
sob5,
soc5,
ios3,
iso3,
oos3,
2 letter words:
ow5,
wo5,
bi4,
bo4,
ob4,
io2,
is2,
oi2,
oo2,
os2,
si2,
so2,