Tilex Mildew... ewwwwww!

I've used all natural cleaners for about 2 years now, but I still have the random bottle of Tilex Mildew cleaner in my cabinet. Today I noticed some mold growing in our showers, so I decided to grab the Tilex and give it a cleaning. For about 2 hours after cleaning, I had such a horrible burning in my throat and just felt crappy! I couldn't believe it!!! I was so mad at myself for using it and threw it all away. Now on to find some mildew cleaning remedies!!! Any suggestions?