I have two of these, one for work and one for home. They are well made. They are 5 star rated on Banggood with 50+ reviews. Similar sizes on Amazon are around $US15+.
One criticism is that they do have a chemical smell when you first receive it. Put it through the washing machine about 5 or six times and you're good to go.
At this price I am ordering three more for gifts (after washing).
What are these for ? How does the "thickening" come into play ?