No worries: The Dettol line of products is called
Sagrotan in German-speaking countries. What you want is
Sagrotan Konzentrat. You should be able to get that in Switzerland. Here's their website:
Sagrotan Hygienische Reinigung & Desinfektion
On the other hand, I have seen Dettol being used in Slovenia and the Maldives, among other places. It should be possible to get it shipped to Switzerland, if you are a very brand-conscious chap or just want that warm feeling of home ;-)
By the way bathtub, sorry I didn't reply to your PM yet, didn't have time yet and have to go now! You'll hear from me tomorrow.