“I want to offer a hand express wax. This will be new to me so I don't know exactly what to offer or what to expect.”
Start at the beginning - demand.
As dual in-bay, assume volume is 30,000. Take rate at full-serve is 20 percent so demand would be 6,000 cars or roughly 20 cars a day or average of 2 an hour.
However, to avoid disappointing customers (i.e. long wait time), capacity should follow carwash. Carwash is designed to meet maximum hour.
Since maximum is as much as three times average, demand for wax might be as high as 6 cars for several hours a day during peak operating conditions.
Typical output for hand wax is 2 cars per man-hour (double if working in teams of two persons).
Since express is no appointment necessary, first-come first-served, figure staffing model to meet demand of one person all the time, two persons half the time and three on weekend.
Another consideration is the nature of the work. Full-serve and flex-serve clean with friction. However, “touchless” does not remove this film. So, wax needs to contain a “cleaner” or swirl marks will be created when wax is buffed.
I recommend Meguiar’s liquid cleaner wax. It can be applied to slightly wet car. It comes off as fast as it goes on, leaves behind absolutely no powder when removed with microfiber towel, and contains synthetic wax (polymer) so it holds up for 60 days and has wet look.
Since time is of essence with express, I would use a “spray and forget it” tire shine product.
I use Driver’s Choice (Greenbrier International, Inc.) $1.00 32 FL OZ bottle at dollar store.
Its water-based, leaves behind “dark satin finish” like brand new tire, blends into rims so no hand touch up needed, no sling and it helps prevent brake dust from sticking on rims.
Door jams are done last with the dirtiest of towels, not wax or window towels.
Hope this helps.