I've used a couple of different types and find that newborn/breastfed poo goes through all of them. You might find you'll prefer fleece or silk liners that you reuse. TBH I don't use liners at all, not worried about having to rince poo off and the sun gets out any poo stains. I just give them a scrub or a short soak every few weeks if they look like they need it.