Work in situ, because a Bull head is built into masonry and cannot be moved. Remove the grates, Flavorizer equivalents and drip tray to clean separately, work the stainless along its grain, and protect the surrounding stone from run-off.
Bull makes American-built stainless barbecue heads designed to be set into masonry outdoor kitchens, and that installation defines everything about cleaning one.
It cannot be moved
A freestanding barbecue can be wheeled somewhere convenient, tipped, and hosed. A Bull head is built into brickwork, rendered blockwork or stone, and it stays exactly where it is.
Three consequences follow.
Everything removable comes out and is cleaned elsewhere: grates, heat plates, the drip tray, the warming rack. That is where the bulk of the work happens, and doing it away from the installation is far more effective than working in place.
Run-off lands on the surrounding masonry rather than on grass. Stone, render and grout are all porous to some degree, and a strong degreaser can mark them or strip a sealer. Protect the surround before you start, and rinse it afterwards.
And the cabinet interior beneath the head is a confined space that collects fat, spiders and, in a Sydney backyard, a surprising amount of leaf litter. It is worth opening at least annually.
Stainless, and the grain
A Bull head is substantially stainless, at eye level, in daylight, which is the least forgiving combination there is.
Work along the brushed grain, never across it, with a soft cloth. Nothing abrasive, no steel wool and no scourer, because a swirl pattern in bright sunlight is visible from the far end of the yard.
Heat discolouration around the burner area is a different thing from dirt: it is the stainless itself changing colour under heat, it is normal, and abrasives will not remove it. Chasing it with a pad only adds scratches to discolouration.
Rotisserie, side burner, warming rack
A Bull outdoor kitchen head usually carries more than a cooking surface. The rotisserie motor mount, the side burner and the warming rack all collect grease and all get skipped, because the main grates are what people see.
Our BBQ cleaning guide covers the grease path, burner ports and the spider problem that affects any gas barbecue left outdoors.
Seasoned or coated, before you choose a product
Bull heads ship with different grate materials depending on the model, and the two want opposite treatment.
Bare cast iron is seasoned, protected by polymerised oil built up through use, and a strong degreaser strips that in one wash. Stainless rod grates and porcelain-coated grates are not seasoned and can be cleaned more directly.
If your Bull has bare cast iron, treat it the way you would a Beefeater: burn off, scrape warm, wash minimally, dry on the heat and re-season with a thin film of high smoke-point oil. If it has stainless or coated grates, that step is unnecessary and the coating is the protection instead.
Getting this backwards is the most common way an otherwise careful outdoor kitchen clean does damage.
What actually goes wrong
Marked masonry from run-off nobody protected against.
Swirl marks on stainless, from working across the grain.
Heat discolouration attacked with an abrasive, adding scratches to a normal appearance change.
A cabinet interior never opened.
Should you do it yourself?
Do it yourself for the removable parts and routine wiping along the grain.
Get someone in for the cabinet interior, the burner ports and anything that has set hard, particularly on an installation where the surrounding stone is expensive.