The first item is a good razor sharp scraper. Every good hood cleaner worth his salt has a number of different scrapers in his toolbox. When a grease duct has inches worth of solid grease built up, the quickest way to remove it is with a scraper. Many things can be used for scrapers such as putty knives, flat-head screwdrivers, straight razors, and even spoons. As long as it's sharp, it can serve a purpose.
The next important item in your toolbox should be a good grease removing chemical. Some hood cleaners prefer mixing their own chemicals to remove the grease for the hood and duct system because it can save a little money. For this, most use caustic beads or liquid. Although it will work, it will not be as effective as a manufactured chemical that has surfactants, rinsing agents and other goodies that will help with the grease removal process. My advice is to leave the chemical mixing to the professional chemists for obvious safety reasons.
The third tool would be a good quality pressure washer. There are 2 types: electric and gas powered motors. The electric motor has the benefits of being quiet and fairly mobile. However it does have some drawbacks as well. It has to be plugged in and it pulls a lot of amperage when under load so sometimes it can be difficult to find a plug inside a restaurant to handle the power. If you are farther away from a plug than the pressure washer's original power cord, then use only 10 gauge extension cords.
The other type of motor is gas powered. The gas powered offers many benefits as well like not having to plug it in. The gas powered motor is also capable of using much higher volumes of water than electric which is a huge advantage when it comes to cleaning. The higher gallons per minute (or GPM), the faster you will clean. The drawbacks to the gas powered motor is the noise and the cost of fueling it.
Now it's not the pressure washer only that makes a good hood cleaner, but how they use it makes all the difference. Some kitchen exhaust systems have duct work that is nearly impossible to access. All the scrapers in the world do not help. The best chemical in the world does nothing if it can't be applied to the surface of the grease. How do you clean those inaccessible areas?
Well, I saved the best tool for last and no kitchen duct cleaning equipment tool bag is complete without a duct spinner. They can be found all over the internet starting at $230 and up. Or, you can make your own for under $50.
for more info :- commercial kitchen exhaust cleaning in Malaysia