Loofah sponges or nylon sponges?
A nurse friend asked me what would be good for exfoliating the skin on her back. She didn't want to use the real loofah sponges made of natural fibers (a kind of squash from the cucumber family) because extra steps have to be taken to clean them because bacteria grow there.
I told her I've been using these natural loofahs for years, but that I had then discovered these pretty little gloves and bath/shower fabrics in textured nylon. I've used them every time in the shower and loved them. You rub them gently over the entire surface. Your skin is gently exfoliated and it is definitely softer. I experimented with not using the gloves and saw a difference, my skin wasn't as smooth. Some people like to put soap on the gloves, it's not my preference because I feel like the soap soaks into my skin and makes it even drier. I use soap, but before or after exfoliation.

For the back, what was my friend's request, I use a cloth with a width of 32 inches approx, made of the same textured nylon. It works great when rubbing from side to side, to exfoliate your back very effectively.

What's great, is that these nylon gloves and cloths can last long enough, unlike natural fiber loofahs which eventually get too soggy. Remember that this is a dried plant, exposing the fibers. Of course both have their advantages., It's a question of taste.
I use two (2) body scrub gloves, it's easier that way. You can also rub your face very gently, around the nose, chin, cheeks; just make sure your skin doesn't have a rash, no acne or not too sensitive.
So to answer the question “Loofah sponges or nylon sponges?” For me, it's “Nylon sponges!” For another person, it could be “Natural fiber loofah sponges”. What matters, is that you take the time to exfoliate. There are several advantages to this. It gets your blood flowing, removes dead skin, your skin breathes better and is softer to the touch.