no you don't need to use liners, some people find it easier to use a liner so they can keep the solids contained on one piece of flat fabric and therefore you don't have to fiddle to get it out of the scrunched up elastic areas. It also reduces the risk of staining to the actual nappy. I personally gave up on using liners pretty quickly as i found they were another thing to fiddle with when doing up the nappy and as i'm the one who removes the solids i'm not too bothered if i have a bit of extra work getting the solids out of the elastic area's. As for staining i have only two slightly stained nappies and i figure as i plan to use them through multiple kids- if they stain a little its only me that knows. And when i used fleece liners i had escaping solids anyway! As for dry pailing- you can chuck what ever you like in there
its your bucket! As far as i understood it dry pailing doesn't mean everything has to be dry. Just that you aren't pre soaking your nappies as alot of people consider it unnecessary as long as you don't leave them for too long.