If you throw away the oil left in the kadai after frying pudi-pakodas during the rainy season, it is not right. This oil may not be reusable in food, but it can be very useful in many household tasks.
From the leftover cooking oil you can remove stubborn stickers and glue, shine wooden furniture, easily open rusty screws and bolts, and give leather things a new-like shine. However, if the oil is burnt, smelly or has been heated several times, do not use it again.