Well, the worst I ever tried was Rooi Perd (“Red Horse” in Afrikaans). But it was my own fault. I experimented with it ”off label” out of curiosity. Have no idea if it is still available. It is a twist rope of dark oily brown chewing tobacco packed in a small round plastic disc. But I did not get it from a tobacconist. It was on the shelf in a Witwatersrand hardware store, in the garden chemicals and insecticides section. The shop assistant told me to plunk the rope of tobacco into a watering can, fill with a litre or two of water and allow it to soak for a few days. Then, sprinkle over the garden plants, roses, hydrangeas, etc. to repel the devouring caterpillars, aphids, whiteflies, Parktown Prawns, and what-have-you. It looked and smelled strong and lethal. I took a few slices off the end, rubbed it out, stuffed into a pipe, lit it, and nearly killed myself. Barf!