If you don't burn incense before divination, is this divination effective?

Of course it works. Burning incense is essential for ancient people, and some of them have to be clean. That's just a form, the purpose is to ask the tester to be sincere. Nowadays, these forms are no longer needed in society. I used six hexagrams to break divination for others and never asked them to burn incense. I just said it myself, as long as the other person is sincere.