Washing-up liquid on leather

Does it work?

Does not work

Refuted by the trade body for finished leather. The commercial interest is real and recorded; the pH and residue mechanism stands independently of it.

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

A dilute surfactant lifts oily soil and rinses away, and it is mild enough for skin, so it reads as the conservative choice. Two things do not carry over from washing a plate. Leather is not rinsed under running water, so the surfactant remains on it; and the surface being cleaned is a polymer finish rather than glazed ceramic, so an alkaline residue has something to act on.

Background

Where saddle soap is the traditional answer, dish detergent is the modern improvised one: mild, at hand, and apparently safer than anything sold in a bottle marked leather. The trade guide groups it with the things it prohibits — 'any strong solvents, abrasives or caustic household cleaners such as soap or dish detergent' — and puts high-pH cleaners at the head of the same list. The objection is pH and residue rather than strength. A finished hide carries a water-based coating, and an alkaline surfactant left on it acts on the finish; because the surface is not rinsed the way a plate is, whatever is applied stays. The guide's technique notes make the same point from another angle: over-applying even an approved cleaner leaves the surface tacky and it then transfers onto clothing, so residue is a recognised failure mode here rather than a theoretical one. What the guide asks for instead is unglamorous — a suction vacuum, a white cotton cloth dampened rather than wet, circular motion under moderate pressure with no more force than a firm handshake, and air drying with no heat.

What it does not do

• The guide names soap and dish detergent without distinguishing dilutions, so the point at which harm begins is not established
• It is published by a body selling leather cleaners and has an interest in excluding household substitutes
• It does not address unfinished or vegetable-tanned leather

What to use instead

• 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.
• Microfibre cloth — Split synthetic fibres with a very large surface area, which lift and trap soil mechanically — often with water alone.