title: Cleaning up partial registrations
body: <p>I am working on a Rails app where users must fill out two or more screens to register.  The registration data is spread across two or three records in two tables.</p>
  
  <p>Of course, users can bail out before registration is complete.  This is detectable as null entries in mandatory columns.</p>
  
  <p>What is the "Rails Way" to clean up these partially complete registrations after some reasonable delay (a few hours)? </p>
  
  <p>In case it makes a difference, I'm deploying on Heroku.</p>