Getting directly to the point, there are six types of whitening shampoos. Each one has its upsides and downsides.
1. Bluing Shampoo
This shampoo type is adding the violet colour on the orange/yellow pallet of the hair and results in vibrant white hue. This direct white is used for immediate but short term results. Another downside is that if abundunt shampoo is used, the end result will be the unwanting white-blueish hue on the coat.
2. Clarifying shampoo
Clarifying shampoos have a low pH (3-4), much lower than the skin of the pet (6-7.5). They are amazing for crisp coat and dirt removal but have a corrosive effect on the hair shaft in order to reveal the white character of the coat. They cannot be used very often and the coat needs to be strongly hydrated after their use.
3. Bleaching Shampoos (with or without Hydrogen Peroxide)
Bleaching Shampoos have a high pH, which is much higher than the skin of the pet. They corrode the hair and dissolve the colourants that have penetrated in the hair shaft, giving a strong whitening effect but may cause damage if they get in the eyes. Also they should be used for a few minutes/seconds otherwise they might chemically burn the hair shaft turning it into yellow.
4. Enzymatic shampoos
Enzymatic shampoos are dissolving certain substances and colourants in the hair, giving a nice whitening effect but they need many applications to give the best result. Sometimes it is possible not to work on certain substances and might be ineffective.
5. Dying Shampoos and Sprays
These shampoos have slightly lower pH (4.8-5.2) and aim in covering the unwanting colourants by binding semi-permanently on the hair shaft. This effect might last a few days and there are many steps/products involved for the process making it a very expensive and complex method.
6. Optical enhancing with light Silicones and natural Titanium Dioxide
Top Dog Colour Plus shampoo is using this unique formula. It contains a special blend of silicones and TiO2 (Titanium Dioxide), which is adsorbed on to the hair fibres and increases the degree of light scattering while leaving a very soft and grease-free result on the coat. Colour Plus shampoo also delivers a truly intense colour without corroding or destroying the hair fibre. It gives an astonishing bright White and can also be used in any coat type such as Silver, White, Black and Brown. The results of the brightness and whitening are getting better every time Colour Plus shampoo is used. The strong upside is that can be used often because it hydrates bot skin and hair and has a very mild character in comparison to the other whitening shampoo types.