How do I keep my bunny from chewing her cage bars?

I let her out for almost the entire day and she still wants out after all that. I've read some people suggesting putting some jalape�o pepper stuff on the bars, but then I read from another source that I shouldn't because it's cruel. I can't let her out when I'm trying to get some sleep, but I don't want her to chew off anything (like paint already on the metal bars.) on her cage bars and get sick. I'm very confused, and if it is okay to put jalape�o pepper stuff on the cage bars, then how do I put it there and what form of a jalape�o pepper should I put there?