How can I filter out specific words in a node body? For example, suppose a user creates a node with body value "Hi everyone. GARBAGE VALUE This is my node." Upon submission, I want to be able to filter out "GARBAGE VALUE" and replace it with nothing (or have a replacement value) so that when the node is displayed, it only displays "Hi everyone. This is my node."

Is there any way to do this? Rules? (Rules is the only module that I have yet to figure out despite trying.)
Apart from the Rules module, 


the Wordfilter module allows site
administrators to filter certain words on all pages.
the Phonetic module goes a step further by including the phonetic characteristics in the comparison as well as a list of profane words.