The Gold version has a residual action that lasts for months, if the roach just walks through the sprayed area it WILL die. Review 2: Bengal Roach Killer Spray – Effective for Apartments Bengal and raid roach killer (has Nylar) is an effective roach insecticide based on permethrin. Bengal Gold Roach Spray isn’t going to be the cheapest spray available on the market, but it does work the best. I spray the base of the door frames of every room as well as a few sections of baseboard (roaches hug the edges when they travel, have you noticed that? The product uses the dry content that you can apply to the roach’s hiding spaces, including gaps, splits, and cracks. Bengal Roach Spray Review – Best Roach Killer The reason is that because this product has a flushing agent, the chemicals are dry and have a flushing agent. It's really good, very effective stuff, 6 people found this helpful Bengal Roach Spray is a powerful roach spray that contains a highly powerful insecticide called Sumithrin. Bengal Gold Roach Spray 4-Pack Model #92464 (4) BEST Roach Killer on Amazon SAVE $$$ Prevents cockroach reproduction Prevents reinfestation of cockroaches for up to 6 months It is a highly effective solution for roach control. This roach killer is the BEST! Most reviewers found this product to be exceptional at killing and preventing roaches from developing into an outbreak. ). It flat-out kills roaches who are sprayed directly and it renders other roaches who come into contact with the residue sterile, so they die out quickly. Bengal Gold Roach Spray uses the active ingredient permethrin which is often a top-rated chemical for treating large insect infestations in the home. This spray has been created to efficiently kill roaches especially those that live in deep and dark crevices or cracks within the wall.