The instant assays used by the collectors and the home tests all function on the same principle. Neither are more accurate than the other.

3 days before the scheduled U/A, take one more home test again using the first-mornings void. If you still test negative (faint line or not) youre good to go. No need for dilution techniques. Just drink only enough fluids to where you can produce a sufficient amount of urine sample at the collection facility.