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.
trasher trashier tracheary treachery torchere torchier torchiere trochar
rasher brasher crasher trasher brusher trashier brushier nourisher marshier crusher harsher fresher breacher rushier rusher reacher preacher broacher brashier cherisher
trash trashy trachea tracheae trishaw