I've been curious about this in my own practice, but I haven't yet been able to find an example of increasing suffering as having a positive impact on my insight.
Do you remember the book or teaching that that analogy came from? Ajan Chah comes highly recommended from others as well.
Edit: oh I guess the exception is clinging to the Dhamma, like the sutta about the raft.
That's correct: the goal is to end suffering - by means of understanding it.
Thus the understanding is important to distinguish there's indeed suffering that leads to the end of suffering -- like Ajahn Chah using analogy of going to the dentist (in itself is a suffering) to end the suffering of dental pain.