Yes I use Apple Garde on every LV vachetta bag I own or have owned. I do it because I want my vachetta to be stain free of water marks (or liquid marks) and I do not trust myself nor want to be paranoid when using my vachetta bags. So far so good for me. Although my vachetta is sprayed with Apple Garde, I have not purposely or accidentally tested it out to see if the Apple Garde protected my vachetta but I have read and watched youtubers test out Apple Garde and it seems to work. Apple Garde Repellent Spray will not darken or stain your vachetta. When you first spray it on, it will make your vachetta look darker and spotted due to the spraying but it quickly dries and then your vachetta is back to the original state. I do 2 coats minimum but have done 3 coats. Lol. Your vachetta will still patina naturally as well. Also still keep clean hands as it can still get that dark coloring under the vachetta top handle when you carry it by top handle.
I've notice a slight darkening under my Artsy top handle in the middle, my Speedy 20 and my Multicolor Speedy 30 but all are very very faint as I am mindful. It's going to happen as that's your natural oils getting absorbed into the vachetta. Apple Garde is good for liquid, like water and rain, and perhaps soda, or some coffee as it should just roll off if you have a good layer on it. They say shake the liquid off your vachetta and pat the area dry. Do NOT spray the canvas with Apple Garde. A youtuber did it and it made her canvas SHINEY!