Yeah. I have a small pocket knife i carry everywhere, it is stainless. I’ve had it for years, and typically bring it in the water with me clipped to my swim suit (incase i need to cut a tangled rope). I wash it like a dish with soap and water, i use it hard and put it away wet, and it has been fine for years and years.

After all this, i took it on a single trip in salt water, it spotted with rust that night.

I also have a sig938 sas which has a stainless slide. I keep that dry and oil it on occasion, and yet that one spotted with rust within a year despite me taking good care of it.

Different grades of stainless make it different grades of rust resistant. Kind of like calling IP67 electronics like the iPhone 7 “waterproof” when they can only really withstand splashing