Bright brown coating either from water or from smoking a husband. Skirting boards are white.
It is useless to wash, only it will be worse. Polyfoam has a porous structure capable of accumulating dirt. I would paint with water-based paint and varnish. Or paint with a special water-repellent paint. Such options are very popular with the Scandinavians, they do not always stick tiles on the walls, use special textured paints, they say it is very practical.
You can try to wash with ordinary detergents that you have in the kitchen, for example, dishwashing detergent or liquid detergent for washing clothes. But do not use washing powders, as they contain abrasive particles and this can leave marks on the baseboard. If detergents do not help, you can try to wash with whiteness. Since your skirting boards are white, the whiteness should bleach them. Well, if all of the above does not help you, then you can paint the skirting board. The paint will give a fresh look and skirting boards will be like new.
Care for wooden skirting boards
It is easiest to clean such skirting boards with a damp cloth. As a rule, wooden skirting boards are covered with paint, so it is not afraid of moisture. If you need to wash off strong contaminants, such as grease marks, if the baseboard is in the kitchen, you can use the usual dishwashing detergent. Soap solution is also excellent. After that, wipe the foam and dirt with a dry cloth. Microfiber rags will do an excellent job of this task; they absorb moisture well.
With persistent stains, for example from paint, things are somewhat more complicated. Here you can use abrasive cleaning powders. To begin with, check its actions on a small invisible part of the baseboard and only after that use it to clean stains. If the wooden baseboard is painted with a matte paint, you will have to use a soft sponge and liquid cleaners. Otherwise, you can ruin its appearance.
Plastic is the most unpretentious material to care for. Such products are absolutely not afraid of moisture and are easy to clean with ordinary detergents. However, plastic skirting can easily be ruined by harsh abrasive powders and various solvents. Do not wipe them with alcohol-containing liquids and especially chemical solvents - gasoline or kerosene, they will leave traces and severe damage on the surface. After such cleaning, the skirting board will have to be completely replaced.
Rubber skirting boards
Skirting boards made of rubber or vinyl are easily cleaned with wax removers. It is enough just to spray them with this liquid and wait a few minutes until the remedy works. Then wipe with a damp, clean cloth. Rubber and vinyl are not afraid of water and are difficult to spoil. Coarse brushes and solvents should also not be used.
MDF skirting board
MDF is a material based on wood chips and special glue. These skirting boards do not tolerate moisture well and should not be used in kitchens or bathrooms. For daily dusting, an ordinary wet cloth is perfect. It is enough to simply wipe them periodically. If a stain forms on the baseboard, you can remove it with a liquid cleaner. It is permissible to use mild solvents such as alcohol or nail polish remover. Before you start cleaning it, conduct an experiment in a small area. Some varnish coatings may not withstand such handling.
Skirting boards made of ceramic or metal are easily cleaned with a steam generator. However, this method is not recommended for rubber, wood and MDF. These materials may come into complete disrepair from such cleaning and will have to be replaced with new ones.