BlankSlate class which has only the reserved and protected methods based on the builder example: https://github.com/jimweirich/builder/blob/master/lib/blankslate.rb

blankslate.rb

class BlankSlate
  # BlankSlate provides a class with only the bare-bones recommended methods
  # without, you know, breaking ruby really really bad...

  # go through every method
  instance_methods.each do |func|

    # if it's a reserved method, don't remove it << these methods actually
    # prompt a warning if you try to remove them!
    if !func.match(/^(__|instance_eval|object_id)/)
      undef_method func
    end
    
  end
  
end

updated gist, no longer uses #send method to call undef_method