Natural vs. Chemical: Flea Shampoo Showdown, Tested for Pets We arrived at the Wondercide - Flea & Tick Shampoo for Dogs and Cats after weeks of debating synthetic vs. natural remedies. True to its "Powered by Plants" promise, our pets tolerated its botanical essential-oil blends without irritation. The 12-ounce bottle poured smoothly, lathering into a satisfyingly rich consistency that didn’t strip their skin of moisture. Active ingredients like peppermint and tea tree worked quickly on live fleas but required multiple washes for heavy infestations. While we admired the eco-conscious formulation, we noticed some residual scent. Overall, Wondercide proved effective, gentle, and a welcome alternative to harsher chemicals—though we’d recommend it for light-to-moderate pest problems. The debate’s resolution? We’re fans of its balance, though occasional reinforcements might be essential.