Can I threaten to throw out my roommates dishes?
That sounds violent. Why do you want to destroy your roommates possessions?
My roommates don't help me around the house at all.
If your roommates don't help you around the house then I can see how angry you must be, but leave their possessions intact. They will sue you for destroying their property. You should just keep nagging them until they finally have and do more around the house.
Nah, I'm going to say that they are lucky that they have their dishes to see if it works.
It will probably not help to threaten them like that. They might do something to spite you. Just talk to them and treat their property like you would your own.