Nudity in Saunas and wellness

Hello, I'm planning to visit a few wellness places in Switzerland such as Rigi baths and Leukerbad therme.

I see on reading some of the reviews that the Saunas here are textile free.

As someone who's been to Saunas and thermal baths, but not textile free ones I'm unsure of the experience.

Will it be a bit weird as a first timer there ? I know most people probably are very used to nudity as a way of wellness and there is nothing sexual about it. But still the mind doesn't settle. What if I get an erection?

Would appreciate any insights to enjoy the textile free zones and hopefully so that I can keep going back.

I'll be going with my wife, for context .