Jacob,
When you say you put GG4 liquid in your pure water for upstairs, you aren't actually saying you contanimate your actual water with it are you
I've dipped my brush in my bucket (I use Unger liquid for my trad work) when I've been doing a really dirty first time clean, but actually putting Unger liquid or GG4 into your actual water is a big no no!
Any of the specialist liquids do take some getting used to, but their advantage, once you can get used to using it, is that it leaves far, far less residue behind on the glass than washing up liquid.
But whther you use GG3 or 4 or Unger liquid, or any of the other makes, they do take some getting used to, but each to his own.
Ian