I works for you Paul because you are blowing the hair up with amonnia or its derivative and the hair is grabbing color uncontrollably. As I recall your hair is very dark so excess grabbing of color is not much of a concern...anyone with lighter hair it definitely will be. In addition you also state "it took ages for the colour to ` develop` and then the hair didn`t go as deep as shade as I wanted" It should take awhile for the color to develope. The reason is so the color can get into the cortex of the hair before it the small molecules start to combine to create larger color molecules and therefor increase durability (They go in in a small hole and get to big to go out the same hole basically). If the color didn't go as deep/dark as you wanted, you didn't let it process long enough or you simply chose a color that was too light. You probably didn't let it process long enough for the color to develop. That color processes for at LEAST 30 minutes on bio hair. Not much color development occurs in the first few minutes. But the main reason is, all of you using permanent hair color are using the wrong type of color on the wrong type of hair. But to each their own. I won't try to convince you of what I have learned in over 25 years . I wear a level 5 with 60 % gray and have zero issues with excessive fading. I get 6 months out of a piece and only have to refresh the color once in that time near the 2 month mark (because the fabric dyes aren't that good they use) and take no special precautions. But as you said, do what works for you ...what do I know LOL.