I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
couch cutch cooch coach gouache cosh catch cache cushy cuish catchy quiche cachou quaich gaucho gotcha cushaw gauche quitch cash gosh gush
couch vouch pouch touch ouch mouch cutch hotch gaucho boche mocha mutch notch hutch poach touche pooch hootch rouche sauch douche dutch gauche touchy sheuch teuch choush butch mucho much loach louche mooch heuch loch roach hooch nautch coach botch pouchy rotch ruche such duchy chough nucha cooch yuch
coca cock cocky coco cocoa coocoo cuckoo chock chuck chucky