Yes, cherry shrimp clean the tank. Cherry shrimp are bottom-dwelling scavengers that will gladly eat any uneaten food and debris available in the tank. Additionally, cherry shrimp will eat algae and biofilm around the tank, keeping the tank cleaner for longer.
With that said, you can’t entirely rely on your cherry shrimp to keep the tank clean. First, cherry shrimp won’t eat fish poop due to the lack of nutrition. Plus, cherry shrimp produce waste that they won’t consume.
Lastly, sometimes, cherry shrimp simply can’t eat fast enough to keep up with the algae growth rate within the tank. You will still need to clean your tank at least once a month. Additionally, you should change 10-25% of the water every week.