You seem to understand it pretty well
Locationless caches are like regular caches in that there are some that are real easy, and some that are real hard.
For easy ones such as a flag, a round building, a fire truck, etc, I just log it. There are too many of these logged to see if I found a diplicate.
For harder ones, such as a tank, Statue of Liberty, movie set, etc, I search all logs to see if has already been logged.
To search all log entries, click on "View them all on one page" at the bottom of the cache page. It make take a few minutes to load if there are a lot of logs. Hit Control-F to bring up the Find box. I usually search for the city or state.
Now, sometimes I find the locationless I found has already been logged several times. If it is logged more than once, I figure the Cache Owner doesn't care if it gets multiple logs and I log it. It appears that many Locationless Caches are ignored by their owners. I have only had 2 or 3 cache owners ask me to delete a log because it doesn't meet the criteria or has already been logged.
Here is a handy link to a list of all Locationless Caches:
"Honey, we're not normal people. We're the Griswolds. "