Pretty impressed how well that one turned out. Used SUNLU TPU in yellow with 200/50 degrees Celsius at 20mm/s speed on my Voxelab Aquila (upgraded PEI bed and DirectDrive, also used Filament drybox).
This filament to be exact:
Angebot: SUNLU TPU Filament, 1KG Flexibles 95A TPU 3D Drucker Filament 1.75mm Maßgenauigkeit +/- 0.03 mm, Hohe Liquidität und Elastizität, 1KG（2.2Lbs) Spule, TPU Filament für FDM 3D Drucker,TPU Gelb https://amzn.eu/d/7H5TLjr
Looks great!
I made a TPU phone case a while back as well with some neat custom cutouts on the back. I really liked it, but the heavy use/touching made the case get off-color and dirty looking, especially on the edges, with no way to clean it off.
I know you can clean tpu with diluted bleach, did you try anything that harsh?
I’m guessing you could clear coat it to keep it cleaner for longer