You can definitely use a flush drink in addition to the Toxin Rid Detox program. We actually suggest it as a method to help you along, if you are showing "barely there" results on your drug tester at the end of your detox. It will help ensure that you pass the detox without problems.
We have several Flush Drinks to choose from, from the Ready Clean to the Mega Clean, all by Detoxify.
These flush drinks are of short duration, so they should be taken 1.5 hours before your test. Keep in mind they only last 3 hours, so it's important you test within the that time.
If you decide to use a Flush Drink on it's own, be aware that all flush drinks when used alone are long shots. While they can definitely help you pass, the odds for doing so are low for any flush drink, regardless of brand.