I need to know how to pass a hair folicle test. Does anybody know by experience?

Give it time. Time is the ONLY way you will pass the test.

If you are one to believe everything you read on the web, there are kits that are sold. Does not say "snake oil" on them but could well be much the same.
Just like J_9 has told you, time is the surest method to passing a hair follicle test.

Don't trust the ad's with your future, just like everyone, especially J-9, says, you can't depend on any test, unless you are truly clean, just like the advertiser, agencies who administers these tests have ways of seeing if you are using these cleansing agents, to past the test, the health agencies also know the fakes! don't risk your future!