Is it normal when you wash spacers, especially those used for preventer inhalers that a film stays on the insid of the tube? I've not beeb using spacers for long so not got into the habit of washing them regularly. I did it today and there's still what looks like a powdery film on the inside. It says not to rub, just to slosh them in the soapy water then leave to air dry. Is this film normal?