I do vending in IL. I have a self-contained hand-washing sink that produces hot water. However, last winter, I didn't winterize it, so last week, I couldn't use it - due to cracked pipe that I didn't have time to fix.
For hand waching, e use a couple of water containers with spigots that can be opened and will stay open until closed (not the push button kind, in other words). We place a catch "bucket" under the spigot to catch the water. My wife keeps a tea kettle of water on the firebox of our smoker (stick burner) to add hot water (although not required by law).
For dishes, we use small bus tubs for the wash, rinse, sanitize. We fill water from on-site hoses into three/five gallon water bottles.
No need to spend a lot of money. This set up has been approved by two counties and is accepted by the state of IL, too.