Another way would be to use the Wiki search page to search for the text "first hand information". If you only want to look at profiles you manage, add "Profile manager: " and your name.
You may be interested in checking out this:
This category is for profiles that do not cite any sources. All profiles on WikiTree need sources. Can you help? Join our Sourcerers Challenge! http://www.wikitree.com/wiki/Sourcerers_Challenge
The link above lists every profile on Wiki Tree from A-Z that does not have sources.