My vachetta has patina'd already and starting to darken on the armpit area and the one with the Louis Vuitton print on the front, its not too dark but i know its dirt, also on the bottom of our Estrela coz i never treated it with anything, the whole 1 year all i do is wipe her with a clean cloth. That's why i did what Jessica's tip coz i want her to look clean but patina'd. The cloth that i wiped had brown stains from wiping, so that means i have removed the dirt and it dries up fast. The following day, i wiped her several times using the dry microfiber face towel of my daughter and the shine went back and most of all she looks clean again. Just make sure you wring the wet cotton sock hard as in no water coming out that's the time you can start wiping your vachetta.
Let it dry overnight, and then wipe your bags with a dry cotton cloth, all your bags will have a nice clean patina. 
and i didn't put anything after.
