Option: The cat sitter could unplug the Feniska Base and plug it back in after 2-3 seconds. This has the same effect as calibrating the base in the app. The base then restarts and takes about 5-10 seconds to be operational again. Option: If you know when the cat sitter will clean the toilet or they can send you a message when the cleaning is complete, you can calibrate from the app even when you're not at home.