The wrong cleaner takes the finish off along with the dirt

Everything here earned its place by changing an outcome. Nothing about cleaning chemistry and materials is included to round the number up.

Cleaning is a chemical process, not an effort

Soil is removed by dissolving it, by lifting it into suspension, or by breaking the bond between it and the surface underneath. Each of those routes uses a different chemistry, which is why one cleaner struggles with a soil another removes immediately. The same chemistry that attacks the soil is in contact with the surface, so the difference between cleaning and damage is often only time.

Temperature accelerates almost every chemical process, so a cleaner that is safe cold may not be safe on a warm surface. This is why dwell time and dilution appear on labels: they are the parameters that keep the reaction on the intended side.

The main families and what each attacks

Alkaline cleaners break down fats and oils, and they attack aluminium, some coatings, natural fibres and certain sealants. Acidic cleaners dissolve mineral deposits and rust, and they etch stone containing carbonate, damage grout and corrode some metals.

Solvent cleaners dissolve oils, adhesives and inks, and they craze, soften or dissolve a wide range of plastics. Enzyme and biological cleaners break down specific soils slowly and gently, which suits fabrics and surfaces that harsher chemistry would damage. Chlorine-based products are effective disinfectants that also bleach dyes, corrode metals and degrade some elastomers with repeated exposure.

Abrasives and mechanical damage

An abrasive cleans by removing a thin layer of the surface along with whatever was stuck to it. On a coated surface that layer is finite, so repeated abrasive cleaning has a countable number of uses before the coating is gone.

The measurable part is this: scouring pads vary enormously in hardness, and the colour coding used differs between manufacturers rather than following any universal scheme. Very fine abrasives in cream cleaners are safer on hard surfaces and still unsuitable for coated glass, plated fittings and printed markings. Printed control markings on appliances are among the first casualties, and they cannot be restored once removed.

Surfaces that are more vulnerable than they look

Anodised aluminium is durable against wear and vulnerable to strong alkalis, which strip the oxide layer and leave a dull grey surface. Coated glass carries thin functional layers that abrasives and strong chemistry remove invisibly at first and permanently.

Many plastics are attacked by solvents present in general-purpose cleaners, and the damage often appears days later as fine cracking under stress. Natural stone containing carbonate is etched by acids including several found in food, which is a chemical mark rather than a stain. Rubber and silicone seals harden or swell depending on the chemistry they meet, and a failed seal is usually a cleaning consequence.

Safety, mixing and ventilation

Mixing chlorine-based products with acidic ones releases toxic gas, and this is among the most common serious domestic chemical incidents. Combining chlorine products with ammonia-containing ones produces different but also hazardous compounds, so no mixing is the only safe rule. Safety data sheets are published for most cleaning chemicals and describe hazards, protective equipment and first aid in a standard format.

Ventilation matters for solvent products in particular, since vapour concentration in a small unventilated room rises quickly. Classification and labelling systems differ between countries, so hazard symbols and wording on an imported product may not match what you expect.

Where a claim here has not been tested directly it is inference, and it should be read as inference.

A conservative method that avoids most damage

Start with the mildest approach that could work, since escalating is easy and reversing damage generally is not. Test on a hidden area and wait, because some reactions appear after minutes rather than immediately. Follow the manufacturer's cleaning instructions where they exist, as they describe the materials used in that specific product.

Rinse thoroughly, since cleaner left on a surface continues to react and residue attracts soil faster than a clean surface does. Remove soil promptly rather than aggressively later, because dwell time is what turns an easy clean into a chemical problem.

Everything above, in order of what to do first

1. Cleaning is a chemical process, not an effort. Soil is removed by dissolving it, by lifting it into suspension, or by breaking the bond between it and the surface underneath.
2. The main families and what each attacks. Alkaline cleaners break down fats and oils, and they attack aluminium, some coatings, natural fibres and certain sealants.
3. Abrasives and mechanical damage. An abrasive cleans by removing a thin layer of the surface along with whatever was stuck to it.
4. Surfaces that are more vulnerable than they look. Anodised aluminium is durable against wear and vulnerable to strong alkalis, which strip the oxide layer and leave a dull grey surface.
5. Safety, mixing and ventilation. Mixing chlorine-based products with acidic ones releases toxic gas, and this is among the most common serious domestic chemical incidents.
6. A conservative method that avoids most damage. Start with the mildest approach that could work, since escalating is easy and reversing damage generally is not.

The takeaway

Match the chemistry to the material, start mild, and treat dwell time as the setting that does the damage.

The question is rarely which is best. It is which is enough.