I have this same model of tumble dryer and I can't seem to find the secret flap! Can you please tell me where it is? I have got down on the floor and opened the lower left panel, taken out the air filter, cleaned it, removed any gunk in the space it came from and removed a ton of really gross gunk right out the very back and up above as far as my hand would reach! But can't seem to find the flap! any ideas?