I've also read the stories about washing camo in modern powder leaving a UV signature that deer can see a mile off. Strangely, most of these stories can be found on the websites of those companies who manufacture UV killers or washes :???:
I tend to view these in much the same way as the whole Scent-Lok arguments.
What I do know is that my friend and mentor has his cammo washed in the machine and he stalks and guides with great success. Either the deer down here have UV filters in their eyes (like humans) or something doesn't add up.
Often wondered about the UV argument - in truth we will never know - unless you can speak deer
Having just had to wash mine for the first time (jacket was detectable downwind at some distance) I can say that the modern powder does definitely make the clothes brighter - which I think its supposed to do? I'm not sure this is an advantage and I won't be doing it too often.