Every time anyone has claimed to beat DEET it turns out to be a baseless claim. I have worked in the health food and outdoor businesses most of my life and have received samples from everyone. Even the latest; Picaridin lasted less than 60 minutes, anything natural (citronella, lemon eucalyptus etc.) last mere minutes.
If you are in real bug country with swarms of mosquitoes then a minimum of 30% DEET is the only thing that will keep working. I like Ultrathon 33% the most and when it is really bad any 100% DEET product is the only way to go.