Drano gender test?

Okay I did the drano test last night and the color didn't change (which means girl) and I did it again this morning and it turned a greenish color (means girl too). How many of you have done this test and it was accurate? I have twin boys so my husband and I are really hoping for a girl. I'm 19 weeks pregnant today and was supposed to find out the gender tomorrow but due to insurance issues, I won't get to find out for another 2-4 weeks