Bathtub rhymes with:
arab, ballclub, bernabe, bizub, caleb, carob, casseb, cherub, diab, galeb, golob, golub, holub, hubbub, jacob, jacobe, jakab, jakob, kaneb, kassab, kosub, kozub, mccaleb, wachob
Bathtub sounds like:
batavia, batboy, baydhabo, beatify, beautify, betabia, boothby