If your plush toy smells of smoke, mildew or is just plain stinky, stick it in a PAPER bag with some cedar wood shavings in a separate non-airtight container – Open jar, old sock, etc. DO NOT LET THE SHAVINGS TOUCH THE PLUSH TOY though. Let it sit for a few days, weeks, or even months and it will eliminate the odor. Every week or so, stir or shake up the cedar shavings. There’s a product called Cedar socks which are meant to be put in smelly shoes that does the trick rather nicely.
I would imagine that dryer sheets in a non air tight container would work well, also!!