I am not sure what you mean by "dilute ETG". I will assume that the sample was dillute, but that you were also positive anyway. Correct me if that is not the case.
What I believe they are suggesting is that they sent the same sample [they split it] for confirmatory testing.
This will show if there is alcohol or even the breakdown products in the sample.
It will be positive if you have alcohol
I don't think geritol typically has alcohol.
See this link on your supplement: no alcohol
As to whether you refuse the confirmatory testing, ETG is highly sensitive to any alcohol. It typically, however, is not a false positive. It has been critisized sinc it is so sensitive, and within 25 to 50 hours, will often detect any alcohol exposure. If you are on probation, not doing further testing leaves you with the ETG results.
Whether is is an invalid sample, or a positive sample, it will not provide proof that you did not drink.
OK, so that is an initial answer….
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