Thanks for the info, I'll take note of that, makes sense. Appreciate the tips?It's safe to use at 100% mix so don't need to worry about that. It's more a question of wasting it and using more than necessary. The reason I use a strong mix on the brush head is that when you've given a quick go over with the water turned it gets quite diluted so you need to start with a stronger mix when you do it that way.
Spraying it on directly I'd use a weaker mix.