Water Pillow

[shilala]

I can't tell you if those particular things are same as, but I can tell you that we used SAP for shipping chickens lots of years ago. It wasn't long after that I saw it used for cricket feed.
You can put most anything in SAP, but the more salts involved, the less it will swell, so you get a lesser volume per unit of SAP.
When SAP was getting real popular, there was a push by a guy named Gary Something (I talked to him a few times, can't remember his last name) to standardize the grades for SAP. IIRC, it just landed at one grade because it's basically benign, meaning you can even eat the lousy stuff and it won't hurt you.
Instead of grading toward food quality, they set a group of standard grades for product quality that went toward the regularity of grain and how much dust was in it.

All that to say, yeah, it's probably the same stuff.
And...
I have a 50lb drum in the garage. It takes an ounce of my SAP to make a gallon of gel when you hydrate it with distilled water. If you'd like to try it, I'd be happy to send you some.