Very messy. You can adjust water pressure at the nozzle or with adjustable gun. The mess is on your equip and you.You clean up the restaurant mess. Know what you are getting into also , it's a big liability issue. You become part of the responsible chain in a restaurant fire. Insurance, lawyers, court, lawsuits, etc. They try to pin the fire cause on someone and it's usually the hoodcleaner who pays some of the bill, unless you can show paperwork that you did everything by the numbers. The job itself is dirty and straightfoward, remove the grease on everything from hoods, ducts and fans, top to bottom to within a hairs thickness of grease or bare metal. Many companies don't do the inbetween cleaning prefering to clean the filters and hoods which is the part that gets seen. It's not something to take lightly if there is ever a fire where you've "cleaned" and cut corners think of a firefighter falling through the roof and then face up to the life and property loss.