Yep you shouldnt use it unless you use a liner. If you want to use it, then just pop a fleece liner in the nappy. You will prob need to scrub the liners with washing up liquid after a while as they will get impregnated with the cream.
You're not supposed to use nappy cream with cloth, but we have done it a few times with no problems. I never put a lot on, just a little bit and make sure it's rubbed in properly (so the skin is skin coloured and not white). We only use it once in a while though, and our nappies are fine (mostly fleece lined pockets and Easyfits). We've never even needed to strip wash them.
I have ordered little lamb fleece liners and will really only use Drapolene if there is any sign of a nappy rash starting DD was fine never really had any trouble but DS cut teeth through his bum and had the most horrendous nappy rash at 9 months open skin etc etc
Natural nappy balms are fine to use on babies bottom & are much better for them too as there is no nasty chemicals in them. Some ladies on here use waitrose baby bottom butter which is a lovely natural product. Looking online they also sell badger balm which is a lovely product too.