Lio - I use old pieces of jersey cotton sheet. I cut them so that they are the length of the nappy gusset, and four times as wide. I then fold them into thirds, so they overhang the gusset slightly. This means that even if the Tots are a bit rough (line dried), they don't irritate ds's skin. No poo ever gets on the nappy at the sides, or through the liner onto the nappy (like you would get the brown stain with a disposable liner). They are very easy to rinse as no pile for poo to attach to.
DS has food intolerances, so poos up to 8 times a day, yet with these liners it isn't a problem. Also, (sorry if TMI) because he poos so often, he sometimes will poo in an otherwise dry nappy. Then if I was out I would just change the liner (e.g. today he pooed 5 minutes after I had changed a dirty nappy!) and keep the same nappy on as it was essentially dry and clean.
I buy the sheets second hand (the older the better as nice and soft) at charity shops or car boots, so about £1 makes 20. Nearly as cheap as disposables if you wanted to throw them after use!!
I'm just about to cut up a few more (used to hem them, but don't bother now). I could pop you a couple in the post so you see what I mean if you like!
They are also better for ds's bum, which gets nappy rash with fleece liners due to the heat I think.
HTH