Fifty percent of the world’s population is infected with Helicobacter pylori, which can trigger many gastrointestinal disorders. H. pylori eradication therapy consists of two to three antimicrobial medicinal products, but they exhibit limited efficacy and may cause adverse side effects. Alternative therapies are urgent. It was assumed that an essential oil mixture, obtained from species from genera Satureja L., Origanum L. and Thymus L. and called the HerbELICO® essential oil mixture, could be useful in H. pylori infection treatment. HerbELICO® was analyzed by GC-MS and assessed in vitro against twenty H. pylori clinical strains isolated from patients of different geographical origins and with different antimicrobial medicinal products resistance profiles, and for its ability to penetrate the artificial mucin barrier. A customer case study included 15 users of HerbELICO® liquid/HerbELICO® solid dietary supplements (capsulated HerbELICO® mixture in liquid/solid form). Carvacrol and thymol were the most dominant compounds (47.44% and 11.62%, respectively), together with p-cymene (13.35%) and γ-terpinene (18.20%). The minimum concentration required to inhibit in vitro H. pylori growth by HerbELICO® was 4–5% (v/v); 10 min exposure to HerbELICO® was enough to kill off the examined H. pylori strains, while HerbELICO® was able to penetrate through mucin. A high eradication rate (up to 90%) and acceptance by consumers was observed.