white noise is great! We use a track free from the internet (sounds like synthetic ocean waves with a heartbeat on the top) burnt on cd and on repeat on the stereo. For all naps and sleep since 3.5months or so..... And DD is nearly 15mths now. DD can sleep at daycare without it (!!) but i have been too scared to leave it off for naps at her grandparents' house. I say who cares if they use it as a prop, it would be easy to wean off it, just turn the volume down gradually over time until it is gone. White noise was a lifesaver for us, it is a sleep assoication for DD and blocks out household noise that would wake DD up - even the chink of a spoon on a teacup would wake her up! White noise blocks some of that out.
I'm happy with the cd we made. You can search free white noise on the internet and there are tracks available.... And I like that the stereo can go loud too, i have heard some white noise machines are a little low in volume.