Soaking oven shelves in a bag with a dishwasher tablet

Does it work?

Unresolved

Unresolved. The alkaline-soak mechanism is genuine and this register uses it elsewhere, so refuting the technique would overstate what is known. What can be said is that a permissive manufacturer route already exists for this exact part, and that the hack's solution is stronger than its popularity suggests.

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

The proposed mechanism

The explanation below is what is offered for this technique. CleaningHQ has not found evidence establishing that this is what actually happens, and says so rather than presenting a plausible story as a finding.

Prolonged contact with a hot alkaline solution softening and saponifying a carbonised fat deposit so it can be wiped rather than scrubbed. Alkaline soak is a real and well-understood route to burnt-on grease, and this register models it. What is missing is any source assessing this particular combination, concentration or duration, or what an overnight alkaline soak does to the shelf's own plating.

Background

The technique is to seal the shelves in a heavy bag or a bath with hot water, a dishwasher tablet and often bicarbonate, and leave them overnight so the carbonised deposit softens off. Nothing read in this register assesses it, and that is the honest headline. What the register does hold is the appliance maker's own instruction, and it is the opposite shape: oven shelves are the one part of the whole appliance where an abrasive is affirmatively permitted — 'Clean the shelves with an abrasive cleanser or steel wool', then rinse and dry. Everywhere else in that oven a scouring pad is restricted or forbidden. So the hack is not competing with a difficult manufacturer procedure. It is competing with a permissive one. Two cautions the register will state. Automatic dishwashing detergent is strongly alkaline and a carpet trade body excludes it from textile use because many contain bleaching agents — this is not a mild solution, and skin and eye contact matter. And a sealed bag of hot alkaline solution left overnight is a container under no control: it leaks, it is easy to knock over, and it must not be left where a child or animal can reach it.

What it does not do

• Nothing read here assesses the technique, the concentration or the duration
• The manufacturer's own route for shelves permits an abrasive cleanser or steel wool, which is a low bar for the hack to clear
• Automatic dishwashing detergent is strongly alkaline and many contain bleaching agents; this is not a mild solution
• No source addresses what an overnight alkaline soak does to a chrome or nickel-plated shelf

What to use instead

• Mild abrasion — Removing a deposit with particles softer than the surface beneath it. Safe or ruinous depending entirely on relative hardness.
• Steel wool — A metal abrasive that scratches most household surfaces and leaves iron particles behind on the rest — which then rust and look like a stain the surface has produced.
• Soaking — Extending contact time so chemistry can do work that would otherwise need force. Often the difference between scrubbing and wiping.