An important requirement of a googlewhack is that all the search terms must be dictionary words (that is, not proper nouns etc.) Google can confirm this by linking the terms in the blue bar at the top of the search that says "searched the web for..." to dictionary definitions. This method can confirm proper googlewhacks, but not necessarily deny them; Google's dictionary might not be complete. Neither "Tarski prokaryote" nor "monitron pants" are confirmed in this manner.

The googlewhacking webpage is (for the time being) found at
According to this page, the regulations are:
1. Googlefactors must exist in this dictionary . It's so easy to confirm: Google does the work! In the blue bar atop your Google results, accepted terms are linked to, and so appear 'underlined.' No line, no link = Googlethud!

2. Google also is the arbiter of a whack's uniqueness. Look to the right end of the blue bar atop your Google results. If you see "Results 1 - 1 of (any number),' you found exactly one hit = Googlewhack!

3. Google shows you an excerpt of the page you whacked. Look at that text. If it's merely a list of words, No Whack For You!

My contributions (only a few of which work anymore... ah how the web is ephemeral): subterranean wireworks; vaxen astrodome; succotash tactician; toolchest absentees; tolnaftate nostradamus