Do most hotels in Switzerland offer complimentary soap and shampoo?
yes.
The above hotel does, too. Check it out. P
I've stayed in very budget-conscious hotels in Italy, Germany and Austria, and every single one without exception had complimentary soap and shampoo. I'm sure Switzerland is the same...
They all have those things, but don't forget to take you own wash cloth. Those are considered very personal and you must have your own!
We love the Staubach Hotel in Lauterbrunnen.