How to clean the chalk from a kettle (electric warming cup)...easy and non toxic method

I don't know about you but me...in the morning before the coffee I'm like out of this world.I feed my cat and make my coffee in auto mode.If someone ask me something I feel to lazy to give a replay.But as soon as coffee is in the cup day can start.Daily usage of the kettle make it look really bad with a lot of chalk stick to it.My cleaning solution is easy and non toxic plus zero effort.
How I clean the kettle:
In the empty kettle I put 200 ml of the cheapest vinegar and water until the MAX sign of the kettle.I put the kettle on it's stand and push the ON button .I let the water and vinegar solution to boil until the kettle stops.

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I leave the hot solution in the kettle for 30 minutes then I drain it and rinse it twice with cold water.I leave the lip open for 30 minutes and then I can start to use normal the kettle.

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