Suckers and candy wont come out with Folex but it's great stuff and will likely do a nice job on everything else. Lowes sells it in a trigger spray bottle or gallon. Get a gallon, useful around the house and more reasonably priced for the amount you get. You're going to need some heat for candy in most instances, a steamer works well, or a a carpet extractor but have to be careful soaking everything, zippers and hooks like to rust as it may dry for awhile depending on weather conditions and where you store your vehicle.
It smells awful but if you take clear ammonia, get from Ace/Lowes easily while you pick up Folex. Mix it 2oz to a 32oz spray bottle, the rest with water. Works quite well at general cleaning and stain removal. As always when trying something new test upholstery for colorfastness on a hidden portion. I've never had issue on the probably 300+ vehicles I've detailed but don't want any surprises. Using a white towel is advised since you never know how it may release dye from what you're cleaning with.
Do a thorough vacuum before any cleaning of course. Water mixed with granola will be the end of your sanity. Careful with yogurt, that can get nasty quick and a lot of the children's types have coloring that really like to stain though likely less noticeable on charcoal.
Our children learned early no eating in the car unless absolutely necessary. I add time to stop for any trips we take to stop somewhere or eat before we leave/get wherever. Despite being clean enough to eat right off almost any surface in my vehicle that's a hard no 99% of the time. Water is all they bring to the back seat as well. I used to co own a detail shop and have seen everything. Figured I don't get paid to clean my own car so it's never dirty...