You do not need anything to participate in Pest Control, but a combat level of 40. That combat will give you access to the pest control boat for beginners. If you have combat of 70, you will get access to the intermediary boat, and with a combat of 100, you are going to get access to the veteran boat. Participating in a game of pest control is completely free. You do not need any gear or anything else. Of course, you still need to get to the island. This is also free if you use the minigame teleport method and the squire in Port Sarim.