You could always cancel the bag order & just use a bungee cord to keep the lid on & put it inside a garbage bag to & from the campgrounds instead of cleaning the SJ before & after in order to keep the bag clean that you are using to keep the camper clean.
Or, you just could put it in the garbage bag to keep your SJ bag clean, which you are buying to keep the camper clean.
Or, you could clean the SJ before & after, use a bungee cord to keep the lid on, & skip the garbage bag since you cleaned the grill already.