I had the honour of doing this when on my own for a weekend in Scuol.

The experience was great - very relaxing, especially at the end when they wrap you up in warm blankets and you can have a snooze......BUT.......
as I was alone and sans partner, they "paired me up" with an old chappie, complete with beer belly and chest rug........
Luckily for me, he was very polite and didn't stare at my naked body - though I did catch him sneaking a look on a few occasions.......tee hee.