Per searching I've seen a few threads about Hygrolon alternatives posted up and one of the most recent mentioned some fabric found at Joann's. Per some regular time wasting last night on Amazon I stumbled upon something that looks almost familiar that is used for speaker covers and is used to wick away moisture.
This got me curious so I searched specifically for "Hygrolon" and a handful of similar items were in the list. I wonder if these will be decent alternatives. It's been a while since I priced out Hygrolon, but it was not always in stock and when it was the sizes of the sheets were limited and due to supply and demand had a cost associated with the limited supply. Things might have changed now, but I figured I'd ask.