So right now I have an implementation of delayed_job that works perfectly on my local development environment. In order to start the worker on my machine, I just run rake
Even if you run it from your console you 'buy' worker dyno but Heroku has per second biling. So you don't pay because you have 750h free, and month in worst case has 744h, so you have free 6h for your extra dynos, scheduler tasks and so on.