You know I have heard that before about plastic containers. And yet to this day I have not had any off tastes or oders from doing it this way. I used to use mason jars, until my wife started getting upset over her jars beings used for pot! lol, imagine that! I have heard, read and seen so many different ways of curring budd that it makes my head spin just thinking about it. One thing I like about the plastic containers I use is that the THC that does fall off the budd is easy to clean up and smoke. I just use a credit card to scrape up the stuff and then load it in to my pipe. Fantastic stuff to smoke.
As I always say "Each To His/Her Own" The main thing is not to allow your budd to dry out way to much, or allow it to sit wet in any kind of container allowing it to get moldey, YUK.