Question

Why should bilges be kept clean and free of oil drips?

Answer 1

Because the bosun might have you flogged if you're responsible?

Explanation:

Any combustible material in a bilge is a potential fire risk. In the glory days of the English navy, so I have read, sailors would chaw tobacco instead of smoking it, as open flames and gunpowder would be intolerably risky. Since a bilge would be pumped out, you would also want to minimize the risk of pollution of the waterways. All of these answers are speculative.