If you have any space at all, I cannot recommend luffas enough. They are very satisfying and easy to grow, they just needs sun and lots of water.

Last year, I grew one plant in a 14inch pot with an upside down tomato cage and a few bamboo sticks. I harvested 10 sponges. It was maybe 5 ft tall in the end. These pictures were before they dried out and I peeled away the husk.