I personally prefer the Frog Toggs cooling towels. My wife prefers the ones with a little more of a dry feel to them (I find the Frog Toggs feel cooler, but that just may be me). We had some of those Mission brand ones that you snap, then my wife also bought this one and liked it:
https://smile.amazon.com/gp/product/B06Y1FD6PR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The Frog Toggs also have ones that are shaped a little better for draping over your neck.
We just bought some insulated Camelbak bottles for this trip to keep water colder and also not have the bottles sweating and getting everything wet. When we had the regular Camelbak bottles before we'd fill them up with ice and water but they'd warm up pretty quickly still. We also used Freaker brand bottle cozies that fit almost any bottle (I love these things:
https://www.freakerusa.com/).
Last, I've always liked Emergen-C vitamin packets to put in some of the free cups of water you can get. You can get them almost anywhere nowadays, and they are marketed more as a vitamin packet now, but they have been around for about 40 years and were originally made and marketed as a sports electrolyte drink. When my wife was feeling nauseous from the heat one day, sitting inside the pizza quick service place in Animal Kingdom and drinking one of these helped her bounce back pretty quickly.