Trash can be in the form of a pizza, chicken leg, banana peel, apple, and rarely liquid. You can find trash at other restaurants. If you leave your restaurant closed or untouched, trash will fill your restaurant. The Janitor is responsible to clean it up, awarding 1 Coin and 1 Gourmet Point.
Clicking on trash will clean it up manually, and can be done in your own restaurant or by visiting a friend's restaurant.
In Restaurant Streets, having a Soaring Crystal on display will transform some of your waste into crystals. Cleaning these up (with a Janitor or manually) will award 3 - 4 Coins (instead of the usual 1), and 1 Gourmet Point.
It seems that having more Soaring Crystals will transform a higher proportion of your trash into crystals, but you would have to clean over 20,000 crystals before you break even with the cost of buying the Soaring Crystal (costs 60k coins) in the first place. It seems to be more of an incentive for your friends to return to your restaurant and pick up your trash, and as a way for you to advertise changes you've made to your layout.
There are three awards associated with picking up trash, depicted by a broomstick mounted on a wall plaque:
- Clearing trash
- Trash Talker, clear 100 pieces of trash
- Rubbish Raider, clear 1000 pieces of trash
- Garbage Guru, clear 10000 pieces of trash