Certified GKH Gardening Expert
Personally, I wouldn't. Many sources say that it is safe, but then they will go on to list many stipulations that could land you in legal trouble. It really depends on how important recycling water will be to you. If you are comfortable following the many strict laws, then it could be a good way to save water.
Make sure that you contact your local extension service before using graywater to make sure that you are not breaking any laws that could land you in trouble.
Here are two articles that will help: