I love air fresheners, I would recommend anything with a strong lemon essence they always seem to last longer and there is some larger candles with a built in essence that even when they are done burning they still continue :)
Im glad I saw this discussion as I still try and capture rainwater now its a pretty good thing to do actually and we tend to get a pretty heavy rainfall here to, if anyone is still interested in some tips there is an article here about capturing rainwater in your hard which should help you out...