You might want to be very careful. I've rescued and treated several ball pythons that have had sheets or towels stuck half way down their throats. These were from feeding accidents where the owner decided to feed on a sheet or a towel and the ball python got some caught in it's mouth as it was swallowing it's prey and began swallowing the sheet/towel right along with it. The size of the sheet/towel makes it quite impossible to swallow and can turn into a huge problem. There's a chance that the snake will just push it back out, but I've also seen first hand where it has to be removed.

-adam