Question

why should oil and ghee not be decomposed of in an open drain ??

Answer 1

Because it form slit which can block the drains and sewage lines.

Answer 2

Here is your answer mate ↙️↙️✅✅✅✅

Because oil and gheeare full of fats that hardens and block the sewage pipes in the open drains fats block the porosity of soil which affects its water and filtering of water efficiency.
That's why oil and ghee doesn't decomposed in an open drain.

Hope this helps you mate ✌️✌️✌️✅✅✅
Happy 2 help ...☺️☺️☺️✌️✌️✌️✌️