Is it possible that the problem is that you have not designated in your policy the proper frequency and standard that they should be laundered at:
"All personnel have been instructed to launder their uniform after each product day used, in hot water, and with a cleaning detergent."
I'm fairly new to FFSC22000 so bear with me but from what you've said I have to wonder if that might be the part they are looking at not being specified.
At one of my previous companies the Quality Manager decided while going into FFSC22000 to have an outside company, CINTAS, provide and launder all of our uniforms rather than having the company supply them and the personnel wash them.
His reasoning behind this was that most people wash their clothes in warm or cold water and that is not sufficient to sanitize the clothes. He said that all work clothes should be washed in hot water to ensure they are fully cleaned.
I don't see a specific requirement in 13.4 that you have an outside company wash them nor that the company itself has to so I think if you spell out the requirement as a trained issue you might be alright.
Any other ideas guys?