Do natural essential-oil flea sprays actually work?

Verified-purchase reviewers and the manufacturer cite high contact-kill rates, but the effect is short-lived and high-trust dog and cat subreddit threads repeatedly warn that cedar, lemongrass, and peppermint oils can trigger toxic reactions, especially in cats. The consensus is that natural sprays can help as a repellent supplement but are not a reliable standalone solution against an established infestation.