|I just realized I'd used "snap-in liners" twice but with different meanings! You both seem to have figured out what I meant, though: the plastic liner for the g-pant and a snap-in/Sandys absorbant booster.
I tried this for a little while today. The liner did bunch up a bit, but it did work to absorb a small pee that DS did who knows when. I maybe try this again when I'm pretty sure he won't poop! I'm not convinced it offers much advantage over a diaper unless he buys into the psychology of its being something special and different. Maybe I should just use one of the flushables that I received, since I'm also curious to see how it would fare in my compost bin!
On a side note, I've always read about some people using L Sandys like pull-ups but couldn't see how that would work, since my experience was with my SuperChunk. With DS#2, though, it's a completely different story, and with his being a scrawny 26 lbs, I can even pull the OS up and down!