Forget the use of drop-in additives. They will be detected when a validity test is run on the sample. Yes, there are instant "cup" tests which feature adulterant panels and their use has increased in recent years. The additives are detected when the sample gets flagged for excessive nitrites, high chromates, and/or an abnormal pH.

Since youre planning on sneaking something into the test site, you might as well sneak something in that will be far more effective than drop-in additives - a clean persons sample or synthetic. Since employment-related tests are not observed unless youre suspected of tampering, artificial delivery systems like the Whizzinator are totally unnecessary.

Read up on N2's Substitution 'sticky' thread for tips on heating and stashing a sub sample.

Besides, when the pressure is on, its easier to use a sub than fumbling around with two additive vials in the bathroom stall.