The oxi action stain remover from HG can be used as a detergent enhancer, pre-wash detergent, soaking agent or directly on the stain as an oxi fabric stain remover. There are rings marking various amounts on the inside of the cap.
I don't know if I'd want to use it too much unless I could find out more about its environmental impact. However, there's no doubt it works. Some materials just smell every time I take them out of the washing machine. Tried loads of things. This is the only thing that's succeeded so far.