Most drug tests do not screen for GHB. In fact, it's very rare to test for it, unless they are specifically looking for it. Almost all metabolites are out of your system within 24 hours.
Most is undetectable within 12 hours or less. The most extreme cases might be detectable at 24 hours or less. When dosed in an IV (I know..but thats how most research was done) it has metabolized into common undetectable metabolites within 5 hours.
Full circle is correct. I heard a Dr. on the radio speak on the subject for about 30 minutes. It cannot be detected dont worry. I was on federal probation that tested EVERYTHING and every test that I took I was "G" up! LOL!
Dont sweat it bro