There was an ig nobel prize awarded for using stamps as an overnight test for erectile dysfunction.
A stamp technique was developed to detect complete nocturnal erections for the evaluation of impotence. The test correctly detected complete nocturnal erections in 22 potent men and absence of complete nocturnal erections in 11 impotent men (P value under 0.001). This is a simple, useful screening test for organic impotence. https://www.goldjournal.net/article/0090-4295(80)90414-8/
> if you have erectile dysfunction then it's a 10% disability claim. They take you at your word, no "proof" needed.