I have to say that I don't agree with oiling feed pellets. I am fairly sure that it has been shown that the high oil content of trout pellets is bad for coarse fish. Thus a low oil pellet is sold for feeding carp and the like.
And re breakdown of Skrettings. The following picture shows 2mm pellets after 22 hours in water. They were in the same condition when thrown away four hours later. I would expect them to be eaten long before reaching this length of time in the water.
If you use a rig and catch plenty of fish on it, why change it for a new rig that may fail on the first fish you hook?
The knots and strength have been tested, the hook length will be the weak link and as long as a fish hasn't gone through a snag or under a platform it should be fine. I'm happy to use the same rig and hook length multiple times until it fails, the hook goes blunt or I see a weakness in it.