Unless your snake is sick or retarded, he won't be drowning in his water bowl.
Papertowels won't hold much water without being constantly wet. This can lead to a host of problems. Dry is fine, wet isn't.
Aspen will keep the humidity up longer without having to have the entire bottom of your cage wet. You can keep a corner wet if necessary and a misting will take longer to evaporate should you go that route.
A humid hide may help out too.