A cabin is eleven materials, not one surface
Gulfstream's own completion center handbook gives cabin cleaning a chapter to itself — Chapter 12 — and inside it there are separate procedures for wood, granite, Lexan, vinyl laminate, plating, stainless steel, leather, vinyl, Aermat rubber, carpet and fabric. Eleven materials, eleven methods, written by the people who built the cabin. It is specific about why that matters: the urethane wood finish is non-absorbent, so it has to be cleaned before every third polish or the polish builds up, and a silicone-based household polish — the handbook names Pledge — leaves an oily residue that can prevent a later repair to that finish. Treat a cabin as one surface and you get one result across eleven problems.
Why a clean usually gets further than the owner expects
Most cabins that look finished are carrying years of accumulated residue rather than wear. Dull leather is usually a film. Grey carpet is usually soil held in the backing. An odour is usually a source nobody has reached rather than the cabin itself. The catch is that the quick methods are the damaging ones: aggressive cleaning of seat covering materials and carpet can strip the fire retardant out of them, beater-bar vacuuming does the same, heat-drying carpet above 100°F shrinks it, and spotters containing trichloroethylene or MEK have no business aboard an aircraft. Worked slowly and correctly, the same cabin comes back a long way.
The honest limit is material failure
Cleaning restores condition. It cannot restore a material that has gone. Leather with the finish worn through at the bolster and the armrest edge will clean up and still read as worn, because the color layer is no longer there. Veneer polished past its lacquer does not come back with more polish. Foam that has collapsed is a seat you sit into rather than on, and no amount of upholstery attention fixes that. Carpet worn to its backing is finished. If you want a quick test, clean a hidden panel and compare it with the panel you touch every flight. The gap between the two is the part cleaning cannot close.
What refurbishment carries that a clean does not
New interior materials have to meet the flammability rule in the aircraft's certification basis, and the shop has to hold the evidence. For transport-category cabins under 14 CFR 25.853 that means vertical burn testing to a 12-second or 60-second standard, average burn length limited to six inches, average flame time after the ignition source is removed limited to fifteen seconds, and smoke and heat-release testing where it applies. Lighter aircraft are certified to a different basis, so the applicable test depends on the type certificate rather than on the material. That paperwork is why the work goes to a completion center and why refurbishment downtime is counted in weeks — lead time on materials, testing, installation and records — while a deep clean is counted in days. A clean is not a smaller refurbishment. It is a different purchase with a different deliverable.
The failure mode of choosing wrong
Both errors are expensive, in different currencies. Commissioning a refurbishment on a cabin that only needed cleaning buys weeks out of service to discover the interior was fine. Cleaning a cabin whose materials have failed produces a clean, still-worn cabin and an owner who has paid to be disappointed. There is a third error, quieter than both: a cabin cleaned with the wrong chemistry. Silicone polish on wood before a repair, bleach taken aboard, household products chosen for speed. Every procedure in that handbook opens the same way, with an instruction to test somewhere inconspicuous first, because two fabrics of the same fibre content can behave differently.
What changes the answer
A sale changes it. Clean, present the cabin honestly, and let the buyer spend on their own taste rather than yours. Charter changes it, because a cabin in constant service holds better on a cycle than on a rescue. A heavy maintenance visit changes it, because interior work then spends downtime you have already committed rather than downtime you have to create. And there is a middle that suits a lot of aircraft: replace the carpet, which takes the hardest wear and dates a cabin faster than anything else in it, and deep clean everything around it. That combination changes how a cabin reads more than any other decision short of a refurbishment.