I should clarify my previous post . . . when I said spray the bitter apple in the face, I actually meant near her mouth so that she would get a little taste of it. I would never spray anything into my dog's eyes.
I guess every dog is different, but I found the bitter apple spray really deterred Sadie from chewing. I have some large floor plants and when we first brought her home she was really going after them. Even though they are not listed as being poisonous, you never know, so I would use the spray on the bottom leaves and it really worked. She never goes near them now.
Of course you can't spray everything in your house, so crating is always the best way to keep the dog safe when you can't be supervising her. But even when we were right there with her, she kept going over to the plants so I found the bitter apple to be just the thing to stop her from shredding up my plants and possibly making herself sick.