Disabling Rails middleware for some actions but not all

It seems that ActionDispatch::ParamsParser is quite slow for some requests, in particular when there is a large JSON request body. I'd like to disable it for these requests, but for most of my application it works great. Is there a conven开发者_StackOverflow社区ient way to disable the ParamsParser for some actions without removing it from the middleware stack entirely? This is using Rails 3.0.9.