Trouble finding alcohol free RV antifreeze this season?

I ordered in a couple gallons of alcohol free Propylene glycol when I winterized my boat. I didn't have any trouble finding it online. I got it from an online marine retailer. I think it was West Marine. I didn't even try the stores. Our nearest Home Depot is about 30 miles away but then it's 15 miles to the nearest traffic light.

What's with all the "vegetable based" comments? I've never heard of such a thing. It's propylene glycol.