Hi, and welcome! I happen to have a Netepur bar from a friend who was an H2O at Home rep before they stopped shipping to the US. Here are the ingredients: Sodium palmate, sodium cocoate, tetrasodium etidronate, sodium hydroxide, aqua.
Basically, it is a lye soap made from palm oil and coconut oil, with EDTA as a chelator. I'm pretty sure they've also removed the glycerin. I say that because they list the "out of the pot" ingredients: palmate and cocoate - and there is no glycerin listed. That would make it tricky to duplicate at home. However, they also list sodium hydroxide, which normally would not be included in out-of-the-pot ingredients since there should be none left after saponification. So, it's hard to say for sure.
Based on the amount of bubbles I get from my Netepure bar, if I were going to attempt to dupe this, I'd start with 60% palm, 40% CO, 0%SF, and EDTA at 0.5% of total batch weight. Higher levels of CO will increase the stain-removing capabilities, but will also make more bubbles that take more time to rinse out. My 100% CO 0%SF stain sticks positively bleach out any stains as well as dyes, so I only use them on whites for the most part.
Have fun experimenting, and let us know if you give it a try. Meanwhile, if you have any PS-80 around, that works pretty well on coffee stains, since it emulsifies the coffee oils.