No, I have not tried it, I am not that crazy or horny yet.

The idea (whether right or wrong) is to activate blood circulation and production by actually scraping your skin to the point of bleeding. 
It is claim it will induce also your body into producing more blood, which they claim it is a good thing, and I respectfully disagree.

I rather have a body massage, do.

I've had limited experience in receiving scraping, but during my TCM training, obviously had it demonstrated, gave it, saw experts who had done if for years give it. I can't say I've been a great fan of it for basic treatments, but as a specific treatment for something, I don't have a problem with it.

It is not only designed to get the blood going, and to induce the body to produce more blood, but to move stagnant qi and blood. It can also help to remove exogenous pathogens (wind, cold, heat).

Be aware that Chinese TCM tends to be more brutal that that practised in other parts of the world - so here, you can expect more pain and discomfort. Although it often occurs, there is no need to bleed after a treatment - just getting redness is good enough (well, for other systems of TCM - maybe not here...).

Can it be effective - for some things, definitely! Expensive.. dunno. probably comparitavely, no... but if you go to some place that says they have the true secret of TCM, and you can only get it done right here.. yep!!!

Tried it once, I relate it to some kind of sick torture that my wife told me to have to find out if my body was healthy. The darker the lines the healthier you are in a certain area. Also comes with cupping, alas in the end, after the massage doctor looked at my back, he turned to my wife and said all my organs were healthy. OMG