Man, the tap test is solid but have you ever asked the seller to let you clean the part first? A dishonest seller will get weird about it fast, and that alone tells you plenty.

Is she seriously saying hairspray is pointless? Try telling that to a bride with a slicked back bun in July humidity. I did a wedding last summer and used Aqua Net on the baby's breath crown, those flowers did not move one inch through the whole reception, and the dry texture spray would've let everything droop by the first dance. The new stuff is great for volume and grip at the roots, but it does not lock a style down the same way. I keep both on my shelf because they do different jobs. That kid will figure it out the first time a client comes back with a half fallen out updo.

Read a post on a crane forum a while back where a guy had the same thing happen, hose looked fine at start up but started weeping once everything got hot and the pressure built. Something about the rubber getting soft with heat and the pinhole only opening up under full load. That lines up with what you saw, dry at pre-start then dripping mid-pick. Glad you had enough pedal left to set it down clean.