I have been thinking similar thoughts Jools! My lot just have newspaper and hay - no hay racks at the moment but I'm going to stick some up again today - but I'm considering putting something more absorbant in the trays to make the paper last longer.
Have you tried fitting the paper flat in the bottom of the trays, so there are no sides sticking up to encourage little nibblers to pull at the paper? That way you can cover the paper up completely, so no piggies pulling it out, but you've still got that between the absorbant bedding and the bottom of the tray, making it a bit easier to remove the yucky litter.
I sympathise with you as I too have the same problem of pigs dragging the newspaper out the hay trays, it's one of the worst things they do, especially when they've only been cleaned out that day!