Found the following onthe draino test:

"If the mixture darkens to a brownish color within the first 10 seconds - It is a boy.
If there is no darkening or color change after 10 - 15 seconds - It is a girl.

When you are done, you will need to carefully dispose of the mixture as it will have a very bad smell and still be very caustic.

The color results above are not very reliable as you will find many different variations of the colors in the results with people interpretting them all differently. This is not a reliable way to determine the gender of your baby, and could have serious side effects to the mom to be if the fumes are inhaled or the mixture gets on the skin. NOT RECOMMENDED as a baby gender prediction method."