Some Experience with Making Bathroom Mats/Rugs?

The success of a bathroom rug really depends more on your environment and habits than anything else. If you like to get out of the shower soaking wet and then dry off, or if you live in a very humid environment, then you will have to loosely tuft only. That way there's a better chance for it to dry between showers. If there're multiple people who also use the shower, then that really makes it difficult to control the moisture. This is an issue with any bathroom rug from anywhere, and why it's best to get a washable rug.

That said, I have had a densely tufted bathroom rug, made primarily with acrylic and backed normally, for about 5 years and have had zero issues. But I live in an arid environment and I dry off before I get out and I am the only one who uses that shower.