Here's what rhymes with knowtoo.
                        
                        
                    
                                to  do  two  too  due  du  dew  tu  chew  deux  bu  ju  jus  peu  pu  boo  chou  chu  doo  tue  pooh  poo  who  you  new  true  knew  blue  drew  u  blew  coup  qu  shoe  zu  lieu  shew  su  sue  vous  fu  lu  rue  stew  zoo  adieu  ado  brew  hu  ku  loo  mu  nu  pew  seu  shu  sou  vu  woo  yew  yu  coo  cou  ewe  feu  gu  ru  shou  thu  tzu  vou  wou  wu  goo  moo  shoo  gnu  roux  thew  whew  into  through  few  view  grew  que  crew  pursue  threw  flew  q  anew  clue  cue  glue  hue  queue  undue  cu  flue  slew  taboo  undo  flu  overdue  piu  tattoo  thru  beaucoup  eschew  fue  hew  mieux  outdo  shrew  sprue  vnto  vue  clew  mew  overdo  redo  strew  spew  zebu  slue  phew  booboo  achoo  screw  bamboo  canoe  renew  accrue  debut  ensue  subdue  untrue  jusqu  skew  shampoo  imbue  outgrew  halloo  honeydew  valuer  endue  foreknew  indue  kazoo  marabou  muumuu  overshoe  overdrew  wazoo  atishoo  review  hitherto  overview  residue  withdrew  avenue  retinue  caribou  construe  overthrew  kangaroo  revue  sinew  askew  ballyhoo  cockatoo  bugaboo  fondue  peekaboo  bestrew  buckaroo  overflew  prevue  overgrew  regrew  interview  revenue  rendezvous  superglue  barbecue  hullabaloo  barbeque  misconstrue