yes, resetting dictionary
Settings>Applications>Manage applications>All>Swype>Clear data...will reset the Swype dictionary. You'll just have to reteach it your way of typing. "Haha", for instance, won't be there anymore either.
outside of that you can try to do one at a time by typing the misspelled word, hitting the spacebar, highlighting the word, and hitting the swype button to see if it will offer you the option to delete the custom word.
I have found that second way is less reliable and that I don't have that many custom words that wont in a very short time be re-entered in everyday use in a day or two.