Vaseline can be used as part of a system to trap cockroaches. One technique for trapping cockroaches is to place bait in a jar and then smear Vaseline along the inside of the jar. The Vaseline makes the sides of the jar slippery, preventing the cockroach from climbing out.
Instead of using vaseline to capture cockroaches in a homemade jar trap, other types of escape-proof barriers can be made from double-sided tape or rolled duct tape. These methods trap the cockroaches but keep them alive so that they can be relocated if necessary.
Other homemade cockroach traps require simple materials such as boric acid paste, baking soda paste or a simple combination of soap and water. Unlike the jar trap, however, these types of cockroach traps kill the roaches rather than simply trapping them.