Twig whisks are still being made, used and sold.
This is a bunch of twigs tied together.
Guess what they are tied together with? More twigs.
The Swedish traditional twig whisk is a true representation of how whisks came to be. A handful of twigs was used to stir something and someone somewhere said "This works great!" and the whisk was born.
When looking for this item you will notice that these are truly not widely availible. These are made by hand by craftspeople.
Examine the photos on this page. The twigs are firm and don't really break. Even though the twigs have some bend to them, they won't snap off very easily.
This is likely the most important factor to look for. If the whisk you are considering looks like straw or fragile, it won't likely do you much good.
When we purchased this whisk it was labeled as a "birch twig whisk".
In addition to these twigs not breaking, they also do not soak up liquid. This utensil is surprisingly functional for what it looks like.
This is the one we bought for this article and is pictured on this page. Description from seller: "It measures 12"- 12 1/2" long. Made in Sweden from Birch branches. This is what our Grandmothers used to make smooth gravy. Price includes shipping via the post office.".