Cleaning agents are substances, usually liquids, powders, sprays, or granules, that are used to remove dirt, including dust, stains and bad smells. Purposes of cleaning agents are absence of offensive odor, avoidance of shame, avoiding the spreading of dirt and contaminants and others. Some cleaning agents can kill bacteria and clean at the same time. Cleaning agents may also be solvent-based or solvent-containing, these last types are called degreasers.

ACIDIC AGENTS 
Acidic washing agents are mainly used to remove inorganic deposits like scaling. Generally, the active ingredients are mineral acids. One common mineral acid is Hydrochloric Acid, (also known as Muriatic Acid) which is typically used for cleaning swimming pools and cement. Sulfuric acid and vinegar are often used in the kitchen to remove crusts, oil and stains.

ALKALINE
Alkaline washing agents are based on sodium hydroxide and/or potassium hydroxide. The alkaline agents also dissipate greases, oils, fats, and protein-based deposits. Bleach and Ammonia are also common Alkaline cleaning agents. Mixing cleaning agents such as bleach and ammonia together can be dangerous or fatal, moreover is not true that mixed together they have a greater effect.

NEUTRAL
Neutral washing agents are pH-neutral and based on non-ionic surfactants that disperse different types of dirt.

DEGREASER
Cleaning agents specially made for removal of grease are called degreasers. These may be solvent-based or solvent-containing and may also have surfactants as active ingredients. The solvent-containing degreaser may have an alkaline washing agent added to a solvent to promote further degreasing. Degreasing agents may also be made solvent-free based on alkaline chemicals or surfactants.
The most common cleaning agents are:

• water (which is a very powerful polar solvent)
• Carbon tetrachloride
• Ammonia
• Sodium bicarbonate
• Calcium hypochlorite
• Cyanuric acid 
• Ethanol or methanol (only in solutions)
• Various forms of alcohol
• Various chlorine compounds
• Vinegar
• Sodium percarbonate
• Sodium perborate
• Coke (mostly for rust)