Trying to do a DRY multi tenancy with mongoid

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery

  before_filter do
    # Find Account_ID by seach for a domain - NOT Refactored yet
    host_id = $memcache_instance.get('hosts/' + request.host)
    unless host_id
      host_db_row = BimbooHost.where( :host => request.host ).one
      if host_db_row
        $memcache_instance.set('hosts/' + request.host, host_db_row.bimboo_account_id, 60*60)
        host_id = host_db_row.bimboo_account_id
      end
    end
    @tenant = request.host
    if host_id
      current_account = BimbooAccount.where( :_id => host_id ).one
      BimbooAccount.current = current_account if current_account
    end
    render :template => 'bimboo/no_site' unless current_account
    return false unless current_account
    true
  end
end

bimboo_account.rb

require "#{Rails.root}/lib/mongoid_tenancy"

class BimbooAccount
  include Mongoid::Document
  field :name, :type => String

  class << self
    def current
        Thread.current[:current_account]
    end

    def current=(account)
        Thread.current[:current_account] = account
        # Reseting scope stack each time we set the current
        BimbooPage.reset_scope_stack
        # Need to call default scope for each model, also, model code in controller
        BimbooPage.default_scope :where => { :bimboo_account_id => account._id }
    end
  
  end
end

mongoid_tenancy.rb

module Mongoid
    module Finders
      def reset_scope_stack
        scope_stack_for = Thread.current[:mongoid_scope_stack] ||= {}
        scope_stack_for[object_id] = []
      end
    end
end