Talk:Cleaning/@comment-208.62.98.98-20121213174707/@comment-3991817-20130208123748

If it freezes after cleaning two island every time, you should make sure you do not clean two islands during the same game session. Cleaning is done in a cycle of 24 hours: once you start cleaning one island you can't clean it again within 24 hours, and all islands you clean withtin 24 hours are added up to form the number of cleanings for that period of 24 hours. So if you need to clean let's say 10 island one hour apart, you will have cleaned 30 buildings in 24 hours, which should be enough to get a Wonder of the World blueprint.