Thanks for your input everyone. I've found a generic nappy squirter online for only $49 and I might just grab a few liner packs and some nappies on special while I'm there.

Just one more question - what do you when you're out and about? Is it easier to use liners in the hope that at least most is caught and you can flush it when you change? I've got a wet bag to keep the soiled/wet nappies in, but I figure it might be better to get rid of as much as possible before we get home?

I have one pack of compostable liners that I will try as well (I got them relatively cheaply at a market recently, but I think the flushable ones are much more cost effective).