The melamine sponge cleans anything

Does it work?

Supported

The efficacy claim is supported — it does remove marks other methods do not, and the abrasive mechanism accounts for it. What is refuted is the scope. This record is filed as supported rather than disputed because the disagreement is not about whether it works but about where, and the where is answered by the material sources rather than being an open question. The restrictions carry the real content.

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

Why it works

Melamine-formaldehyde foam has an open cell structure whose walls are hard and, at the scale that matters, sharp. Drawn across a surface under light pressure with water as a lubricant, those cell walls remove material — both the soil and a very thin layer of whatever the soil is on. The foam itself abrades away in the process, which is why the block shrinks with use. That is an established abrasive mechanism rather than a proposed one; what is not established anywhere read here is any figure for how much material it removes from a given finish, which is why this record describes the direction of the effect and not its magnitude.

Background

The effectiveness is real and the explanation is the whole story. Melamine foam is not a sponge in any functional sense — it is a rigid microporous foam whose cell walls are hard and fine enough to act as an extremely fine abrasive, closer to a very high-grit sandpaper used wet than to a cloth. That is why it removes marks detergent cannot: it is taking a microscopically thin layer off the surface rather than dissolving anything, and it wears away visibly as it does so. Which makes the word anything the problem. On a hard, unfinished, non-porous surface — glazed ceramic, vitreous china, painted brickwork, a plastic garden chair — the trade-off is usually acceptable. On anything whose appearance depends on a coating it is not. Matt and satin paint go patchy and shiny where it has been used, because burnishing a rough microscopic surface makes it reflect differently and the cleaned patch then reads as a new mark. Gloss and lacquered surfaces micro-scratch. Car clear coat hazes. And the coating on a phone screen or a spectacle lens is removed outright. A paint manufacturer makes the general point: what a painted surface tolerates depends on its finish.

Conditions

• Used damp
• Hard, unfinished, non-porous surfaces only
• Always tested first

What it does not do

• It abrades rather than cleans, so the mark and a layer of the surface go together.
• It leaves no protection behind, so a surface it has been used on may soil faster afterwards.
• It wears away rapidly in use and sheds as it goes, so it is a consumable rather than a tool.

What to use instead

• Neutral cleaning — The default that four separate trades converge on independently: a neutral detergent, warm water, a soft tool and a thorough rinse.
• Non-scratch pad — The middle setting between a cloth and a scourer. It is still an abrasive — 'non-scratch' is a claim about a class of surface, not about all of them.
• Mild cream cleanser — A liquid carrying a fine soft abrasive. The trade answer for water marks and light staining on stainless steel — and not the same thing as scouring powder.
• Painted wall — How much cleaning a wall survives is decided by its sheen, not its colour — and matt emulsion is the least tolerant surface in the house.