Its your responsibility as a owner to insure your system is not a liability. If your dead set on cleaning the system yourself, you can do it the old school way. You get a handful of razor blades some steel wool, a caustic chemical, some thick gloves, rags, and a metric ton of time. Make sure you clean every surface that touches the grease vapors. This however will still not pass strict fire marshal code, as your system must be inspected by a authority with jurisdiction in your area.
If you don't want to scratch up your hood, hire a professional. Professionals should hang plastic in a funnel to capture water from a hot water pressure washer. They should not leave a mess, arrive late, do piss quality work, and clean everything completely down to bare metal. They should clean every accessible area in your system with picture report with before and after photos of everything (behind filters aka plenum with view of filter tracks, up the stack to the roof, down the stack to the kitchen, the upblast fan bowl and blades, and any mechanical defects)
Last edited by greesy; 02-09-2017 at 06:47 PM.