The ammonia bag trick for baked-on grease

Does it work?

Supported

Supported for the one component the manufacturer names, and no further. The household trick appears verbatim in the manual, and the same manual prohibits the substance elsewhere on the same appliance — so the scope matters as much as the permission.

This is a verdict on whether the technique is effective. Whether it is safe on a particular surface is a separate question, answered below.

Where not to use it

The proposed mechanism

The explanation below is what is offered for this technique. No evidence establishes that this is what actually happens, so treat it as a plausible story rather than as a finding.

Ammonia vapour in an enclosed space reaches the whole surface rather than only where liquid was applied, and an alkaline environment held against polymerised fat over hours does work that scrubbing would otherwise have to do. The enclosure is what makes it effective and also what makes it hazardous, because opening the container releases the accumulated vapour at once.

Background

Seal a greasy metal part in a bag with ammonia overnight and the fumes loosen the deposit. It circulates as a hack, and the manufacturer's own manual gives it as the method for drip pans: for best results clean them by hand, placing them in a covered container or a plastic bag with a quarter cup of ammonia to loosen the soil, then scrubbing with a soap-filled scouring pad if necessary, rinsing and polishing with a soft cloth. THE SCOPE IS THE WHOLE STORY. The same document prohibits ammonia on the range's metal parts, alongside steel wool, abrasives and commercial oven cleaners. So the permission covers a removable component, taken out of the appliance and enclosed — not trim, not the cooktop, not the door. It is also a genuine chemical hazard rather than a mild one: ammonia is corrosive, reacts violently with chlorine-based products, and a bag of it opened indoors releases concentrated vapour at face height. The manual does not address oven racks, so nothing in it endorses ammonia on them, and nothing permits combining it with any other product.

What it does not do

• The manufacturer gives this for DRIP PANS specifically; the same document prohibits ammonia on the range's metal parts
• It does not address oven racks, and does not extend to them
• No contact time is stated beyond 'to loosen the soil'
• Ammonia must never meet a bleach or chlorine-based product, before or after

What to use instead

• Soaking — Extending contact time so chemistry can do work that would otherwise need force. Often the difference between scrubbing and wiping.
• Detergent — A surfactant-based cleaner. The general-purpose answer for greasy and particulate soil, and the correct first choice far more often than any specialist product.
• Dry soil removal — Taking the loose material away before any liquid touches it. Skipped almost universally, and it is the step that decides whether the rest works.