I have thick, straight hair and I struggle a bit to style it. I have to hold it in the same spot for a long time for it to make my hair wavy, and the whole process takes me 45 minutes. It smells a bit strange when it heats up, and also the result doesn't last very long. On the same day, my hair starts to straighten again, and by the next morning, it's almost straight.
With all due respect, I think it may also be due to the fact that I have very straight and heavy hair, but with a simple French braid, my hair stays wavy for 3 days...