Soak the filters flat in a non-caustic degreaser away from the appliance, and take particular care with run-off, because anything dripping from the hood lands on the fired enamel fascia of the La Germania range below, which caustic products mark permanently and which cannot be repaired.
A La Germania hood is a wide canopy matched to the range beneath it, and the risk it carries is mostly about what is underneath rather than what is inside.
Run-off lands on enamel
When you clean a hood in situ, whatever you use runs down. On most kitchens that means it lands on a stainless hob or a stone benchtop and wipes away.
Over a La Germania range it lands on a fired enamel fascia that caustic cleaner marks permanently and that cannot be repaired. That is worth thinking about before spraying anything above head height.
The practical answer is to drop the filters out and soak them elsewhere rather than cleaning them in place, and to wipe the canopy with a damp cloth rather than spraying it. If you do use a product on the hood, cover the range below first.
Working harder than a standard hood
A La Germania canopy matched to a wide gas range moves considerably more air than a 600mm hood, so filters, impeller and ducting all load faster. Every six weeks is realistic rather than quarterly, and the hood gives no sign that it needs the shorter interval.
The method
Filters soaked flat, never a dishwasher for aluminium mesh, then the impeller housing behind them with the power isolated first. Our rangehood cleaning guide covers it.
Cover the range before you start
The practical version of all this is a dust sheet or a couple of towels.
Before anything happens above head height, cover the La Germania range below, including the fascia, the knobs and the hob. It takes thirty seconds and it removes the entire category of risk, which is otherwise being managed by care alone while you work with your arms above your head and your attention on a filter catch.
It also catches the grey water that comes off a loaded canopy when you first wipe it, which is worse than most people expect and which stains grout and porous stone if it reaches a benchtop.
What actually goes wrong
Run-off onto the enamel fascia of the range below.
Quarterly servicing on a hood doing double the work.
An impeller nobody has reached, which is where the noise comes from.
Should you do it yourself?
Do it yourself for the filters, taken out and soaked elsewhere rather than cleaned in place.
Get someone in for the impeller housing, or alongside the La Germania oven and La Germania cooktop.