Au Naturel isn't at 144 Yonge. That's Tu-nai, which is a great place to iron out the kinks in your back, but it's relatively legit. Au Naturel is the place that you want for some slippery sliding.
Au Naturel is just around the corner from Tu-nai on the same block at 2 Temperance St. Both are at the corner of Temperance & Yonge, which is two blocks up from where you are. But getting them mixed up may get you slapped instead of released....