I oil the ones that I am using as baits. I use bait-tech krill and tuna oil. I have what will be the bait pellets in a small tub (one for each pellet size 4, 6 and 8mm) and I add a small amount of oil, let it soak in over a fw days and repeat. This stops the pellet breaking down and, I hope, makes it more attractive to the feeding fish.