I just used that in December. My first time. It is very strong. I'm not sure of the amount humans should use. I was desperate. First make sure you squeeze the tube to mix the ingredients up . Then when I put it on after about 15 seconds or less you could see it working. Keep away from eyes, it will burn and make eyes water. Keep at least 1 .5 inches away from eyes (I had it too close, didn't go in but it burnt like hell). I put some coconut oil over the ointment so it would be a consistency that you could rub on better. It is real gritty and dries fast. I didn't leave it on overnight or until the next bath, as the tube states. Longest was 20 min. My skin was very red after. I'm not sure if it was from the Nustock or from the mites liquefying and coming up through my skin and me wiping it off. I'm using ground mustard - 1 teaspoon, put into cup, use some water to dissolve, let sit for 10 minutes, then pour into my FULL shampoo bottle. It really works well on my face and body. I still use the Nu Stock in areas that are really bad. Fingernails, toenails, hands, wrists I am in my second round of this nightmare. Had a biopsy last week (finally) Hopefully, results will be in tomorrow, I think I need medication from a doctor and educate myself on long term maintenance. Good luck.