Silica powder to treat tapeworms

My 2-year-old cat has tapeworms. I just ordered silica powder off the internet. Is this safe (as advertised) and how much should I give and in what manner (in food, water, or other)? She weighs 10 pounds or more. Also, I have a dog. Can he catch the tapeworms from the cat? Dog weighs 19 pounds and is 14 years old. Same questions -- how to administer the silica powder (in food, water, or other)? Should I expect cat/dog to have diarrhea with the silica powder? How many times should I treat and how far apart should I make the treatments?

Forum rules are pretty specific about requesting medical advice. You really need to contact your vet for these answers.