Safe effective way to deter my cats from chewing?

I have two 7 week old kittens, and of course being babies they don't realize that the entire apartment is not their toy. Does anyone have a really good reliable (obviously safe) solution? I have been told to try Tabasco sauce (of course the cat my mom had when i was growing up LIKED the taste and it just encouraged him). I have also been told of a product called Bitter Apple - which has worked better, if at all?