How Home Dry Cleaning Works

Pre-treating the Stain

All of the kits advise you to pre-treat or remove stains using the stain remover included. There is nothing particularly special about the stain remover in these kits. It is the same kind that you use to pre-treat stains before regular machine washing, and the pre-treatment process works the same way as well. Most stain removers are simply a cleaning agent in a water-based solution.

The general rule for stain removal is that "like dissolves like." The water in the solution dissolves water-based stains, such as soup. The cleaning agent used is either a detergent or a petroleum-based solvent (depending on which brand you choose). Although the petroleum-based solvents work far better, both detergents and solvents aid in the removal of greasy stains. The informational brochure that accompanies home dry cleaning kits does not specify which of these agents is used in their pre-treatment solutions, and it turns out that the identity of the cleaning agent in the kits is proprietary information. However, given the kits' poor reputation for completely removing greasy stains like butter, it's probably safe to assume that they use detergents rather than oil-based solvents.

The cleaning agent has a number of other important functions, including:

  • Reducing surface tension to help water penetrate fabrics -- in order to remove a stain, water must be able to reach the molecules of dirt on and in the fibers.
  • Loosening and dispersing dirt molecules in the water -- if the dirt isn't dissolved in water or another solvent, or somehow separated from the fabric, it will simply redeposit on the surface of your clothes.

The Dryel and FreshCare kits provide the stain removal solution in a bottle, along with absorbent pads that you use to sop up the dirt after you apply the solution. The process works as follows:

  1. You place the tip of the bottle on the stain, with the absorbent pad underneath on the other side of the fabric.
  2. You gently rub the stain while applying solution.
  3. The soil and grease is liberated from the fabric and dissolved in solution with assistance from the cleaning agent.
  4. The dirt is pushed through the fibers by the pressure you're applying.
  5. The absorbent pad captures the dissolved dirt.

Perhaps it seems odd that a water-based stain remover can be used on dry-clean-only clothes without damaging them. But because you only apply a small amount of solution to a discrete area, you don't add enough water to disrupt the structure of the fibers globally or weaken the fabric, and then you remove most of the water when you blot the fabric with the absorbent pad.

Some product reviews note that the Custom Cleaner kit doesn't remove stains as well as the others, even though it uses a similar cleaning agent. This may be due to the fact that the detergent is not provided in a water-based solution. With Custom Cleaner, the dryer-activated cloth itself is laced with the stain remover, and you provide your own absorbent pad in the form of a clean paper towel. These dryer-activated cloths contain only a trace amount of water. While too much water can damage a dry-clean-only fabric, too little makes it difficult to thoroughly remove all of a water-based stain.

All of the home dry cleaning kits are incapable of removing large stains. Whether water-based or oil-based, large stains must be thoroughly saturated with the proper solvent to attract and remove all the molecules of grime, especially the ones embedded deep within a fabric. Even machine-washable clothes sometimes require special efforts beyond what you can reasonably do at home. For example, grease stains on synthetic fibers, such as acrylic, nylon, olefin, polyester and blends of these fibers are particularly hard to remove. Many of these fibers are specially made to resist penetration by water. Because they repel water, they attract other molecules, such as fats, that also repel water. This makes greasy stains on these fabrics nearly impossible to remove with water and/or water-based detergents alone.

The precautions for pre-treating clothes before machine washing also apply when using these kits:

  • Don't rub the fabric harshly while applying the stain remover. Most dry-clean-only fabrics are not tough and durable, so rough treatment can damage them.
  • Don't treat suede, velvet, fur or leather -- and don't try to home dry clean them, for that matter. These fabrics must go to a professional dry cleaner!
  • Test the stain remover on a small, hidden area of the clothing before applying it to a stain. You don't want to create another problem by destroying the color or finish of the fabric.