I am a plumber by trade and have learned many tips and tricks over the years, but this one is the best by far. If you want to get rid of a horrible smell from the drain outside your kitchen, your first move is to get hold of a cheap pair of women’s tights. Cut off a leg near the top, slide half of the stocking on to the kitchen sink drain pipe, and secure it with a cable tie or piece of soft wire.
All the fats, food scraps and other items that pass through the sink drain water runs away. When the stocking is full of gunge, empty it into a refuse bin and start over. This tip will also help to prevent unwanted blockages in the drainage system.