My family is going on vacation for 9 days and won't have access to a washing machine, so I was very reluctantly thinking I'd have to buy disposables. Then it occurred to me to use disposable inserts...I know of GroVia bio soakers, Flip and gDiapers, but can anyone tell me how these different inserts perform in different types of covers? Like do you really need the same brand cover or are these pretty much inserts that could be used in any cover? And how do they hold up overnight for heavy wetters?? Thanks!