Try these home remedies for killing roaches. Mix Sugar and Baking Soda. This method is cheap, simple, and cost effective. Stir together ½ cup of sugar and ½ cup baking soda. Place dabs of the mixture in strategic spots like behind or beneath appliances, in closets, or near wastebaskets. Roaches are attracted to the sugar, and ingest the mixture. The baking soda gives them gas and ultimately kills them.