My former trailer experts taught me to leave a big gap in the carpet on the bottom center of the bunk. That allows the bunks to dry out, along with the carpet. I also used stainless steel staples to attach the carpet. Gulf Wax, a canning paraffin, is sold in most hardware or grocery stores. One box will last forever if you keep it in the shop fridge. Take one cake in a zip lock bag and leave it on the floor board of the tow vehicle when you launch on a warm, sunny day. When you come back in, before you back the trailer down, rub the aft 2/3s of the bunks with the wax cake. The boat will load and launch easier. Re-apply every 4-6 months. It serves its purpose for easier loading and won't harm the environment (water and fish) and you (severe health warnings) like toxic Liquid Rollers spray. That stuff should be banned.
For those using slick boards, good luck. I had them on my previous guide flats boat (more launches than the average boater) for several seasons and they definitely marked the hull.