Jar where I etch PCB for my projects. It is built with easy accessible materials:
1. Plastic jar (from hardware store)
2. Few sheets of acrylic 4 and 8 mm (from hardware or adverts store)
3. Aquarium heater and air-compressor.

Inside this jar stable temperature set with heater - about 30C. Air bulbs make liquid inside jumbling. Temperature and jumbling intended to speedup etching process.

Used materials are acid-neutral, so only PCB copper layer dissolved inside this jar.

Walls inside force PCB to stay in vertical position. They were cut with china CNC 6040, but if you want to repeat this project you can order cuts from closest advert-company which have tools to cut plastic materials