polymorphic has_many_through with dependent destroy

gistfile1.txt

class Fridge < ActiveRecord::Base
  has_many :soda_ownerships, dependent: :destroy
  has_many :cokes, through: :soda_ownerships, source: :owner, source_type: 'Coke'
  has_many :sprites, through: :soda_ownerships, source: :owner, source_type: 'Sprite'
end

class SodaOwnership < ActiveRecord::Base
  belongs_to :fridge
  belongs_to :owner, polymorphic: true
  belongs_to :coke, class_name: 'owner_type', foreign_key: 'owner_id'
  belongs_to :sprite, class_name: 'owner_type', foreign_key: 'owner_id'
end

class Coke < ActiveRecord::Base
  has_many :fridges, :through => :fridge_ownerships
  has_many :fridge_ownerships, as: :owner, dependent: :destroy
end

class Sprite < ActiveRecord::Base
  has_many :fridges, :through => :fridge_ownerships
  has_many :fridge_ownerships, as: :owner
end