I think he's talking about cutting off a bud, sitting the stem in a cup of water, and letting it suck up the water, like a cut flower.
IMO- it would give it a little flush, but for just a sample I, personally, wouldn't worry about the flushing... I'll clip off a bud to sample, and let it dry without flushing... By sample, I assume you mean, 'I'm itching to get stoned and don't have any weed.' If this is the case, buy some, because each bud you clip off would've gotten bigger.