I've had it about four years or so.
It did and it didn't hurt. How it worked was, imagine they're holding your tongue (some people drool @ that part lol) and then they had the peircing tool. Now this is sort of like a hole punch, the put your tongue in between it and BANG!!. It hurts but only for the split second of the peircing itself. After that you have a week where the tongue is a bit swollen of course but that just gives an excuse to eat iced sweet things a lot. :) You have to use an antiseptic mouthwash for a week yes, but any occurrences heard in apocryphal stories of gargling with saltwater and blood everywhere are not likely.
No regrets.

I've had mine pierced since July 4, 2001. It didn't hurt that bad, just felt like a severe pinch on my tongue and mine didn't swell up that bad either. Everyone is different. I ate Burger King the next day. Also, you HAVE to rinse you mouth out after every time you eat, drink, or smoke. I carried a small water bottle filled with Listerine around with me. It was gross but I didn't have any problems with infections or anything!

My boyfriend has had his pierced for 6 or so years as well. ;)

i've had mine for about 7 months now, and i love it.
the piercing process went really well for me. the piercing didn't hurt at all. the only pain i had was when it really swelled the morning after, but it wasn't anything a little ibuprophen and ice couldn't cure. i didn't have any problems talking at all, and the swelling was pretty much gone in a few days.
i didn't eat any hot foods for the first day, then no solid for a few more, but then was fine.
i would suggest not getting a barbell with metal balls for the first one cause you don't want to chip a tooth the first time you start to eat solid foods again.
i was supposed to wait for two months to change the barbell, but after a month, i was healed enough to change to a smaller size.
so, i'd tell your friend to go for it!