Sometimes even when smoking slowly you can get a gurgle in your pipe especially with bent pipes as gravity has its way and it can ruin the experience. Here is a way not to prevent the gurgle, but to make it go away once it happens. It's really simple, just blow softly into the stem, it might take a few breaths but just blow softly and it will push the moisture back into the bowl and the gurgle will stop and you can enjoy finishing your bowl.