I've used both Canvak and
303 Protectant on my old pup up.
The Canvack stunk for quite a while. I will never use it again!
The 303 worked better, and the smell went away in a couple days. Just got a new to me Roo 183 and treated the side canvas window panels with 303.
When I apply, I get a clean paint brush, soak the canvas with a sprayer, and work it into the canvas with the brush.