It actually stops liquid. Not "mostly." Not "kinda." Stops it.
This is the whole reason the thing exists, so let's start here.
The Accent has an internal waterproof lining sandwiched between the soft outer fleece and the plush sherpa backing. The fiber itself isn't waterproof - the coating lives inside the blanket, which is why it doesn't feel crinkly, plasticky, or like a hospital pad. Liquid hits the surface, the inner lining catches it, and your sheets, comforter, or couch underneath stay completely dry.
I tested this on purpose with a glass of water before I tested it on accident with… other things. Zero seepage. One customer literally wrote that on a king-size bed, the waterproofing was "proven flawless, zero moisture on the bedding."