Is the use for foot fungus justified and helpful?

You did not write what exactly preparation you are asking about. I also suppose that it is about "interfinger" mycosis, not "international". As for the Dermoplasmine balm tagged with the question, it contains plant extracts, and its properties are described by the manufacturer as: "regenerates and protects the skin, as well as relieves discomfort such as redness, itching and dryness. It's a product for everyday use, for the face and body." However, the preparation does not have antifungal properties and such action is not declared by the manufacturer. It can play a skin nurturing role and possibly an auxiliary one, reducing ailments, but it will not cure interdigital mycosis on its own. To combat foot fungus, use a drug with indications in this direction: https://www.gdziepolek.pl/kategorie/grzybica-stop If you are not sure how to treat ringworm, it is advisable to contact a dermatologist: https://www.gdziepolek.pl/telekonsultacja I enclose additional information about Dermoplasmine - it is a cosmetic that can be purchased online, also through GdziePoLek: https://www.gdziepolek.pl/produkty/119170/dermoplasmine-balsam-roslinny-balsam/apteki