Some can end up in the airway, that's why I keep a pipe cleaner doubled over in it to prevent this. I'll actually fill it over the pipe cleaner, and then turn it in circles to make a channel on the new bottom of the pipe that ends halfway down it, to resemble what you would see in a briar pipe. Mixing it in a sandwich baggie, cutting off a corner and then squeezing it out of that will give you a semi-accurate way to extract it into the pipe.