You could use a named query - either by selection/filtering to 'move' these records out of the query, so your query is 'not X'.
In the case below I created 'Cadbury products' query, which gives you 3 choices on the side bar: to move in records that contain this word, move them out, or see all the records by ticking the box next to the query.
2 useful videos:
http://tc.visokio.com/videos/?name=PowerQueryBrushingAndHighlighting&title=Power+query%2C+brushing+%26amp%3B+highlighting&lang=gb
http://tc.visokio.com/videos/?name=SavedQueriesAndSubsets&title=Saved+queries+%26amp%3B+subsets&lang=gb

Some alternatives:

You can use the data subset of each individual view you set up to display only filtered out data as in the image.




Another way is to create a separate text variable which you then make a formula field to detect if the keyword is contained in a specific field.

In the .iok example I created an empty text variable called "Omit" then made a new formula field with this:

IF(
CONTAINS([Field 1],[Omit])=true,[Omit],"Keep")