Plant Cleaning and Shining
Plants collect dust, especially in Egypt, the easiest way is to spray with a leaf shine, sold in Florabel. These sprays can be used once every 15 days or whenever needed. Keep in mind, to use it sparingly, as using it too often can cause the blockage of the stomata - the pores on the leaves - through which the plant transpires, causing in turn the suffocation of the plant. Labels on leaf shine products, recommend testing on a leaf or two before using it on the whole plant.
Leaf shines are not recommended to be used on hairy-leaved plants (such as African Violets and Cyclamens, both these plants should be cleaned periodically using a paintbrush).
A more time consuming and tedious way to clean the plants, is by taking a piece of dry cotton and wiping off the dust, leaf by leaf, going parallel with the veins. Do not wet the cotton with water to clean the foliage, as water leaves white calcium marks, once it evaporates.
A third way is by damping a cotton with beer at room temperature. The only problem with this method is that it collects flies.
A fourth way will be using, a feather duster which might not be that effective.
Never use oils or milk, because they block the stomata.