That if ever you've finished your chips/crisps/pita/other-some-such-dipping-victual before you've finished your hummus/guacamole/salsa/other-some-such-dip, it is important to use your fingers to scrape that last tasty bit out of the bowl/ramekin/other-some-such-dipping-vessel.

In fact, it's imperative.

Anyone who tells you different is in league with The Man.