The biggest problem is that it takes time. PPL are not patient since they are used to using chlorine bleach (which may get banned cuz it's pretty toxic).
I use oxiclean on dishes and clothing primarily. Use HOT water.
For dishes, it wont do jack to the grease, but it will remove stuff from the dishes. I put in dish washing liquid as well, this is to soak btw. I have no dish washer. Then another soaking to remove the film that forms around the dishes. A layer of the oxiclean solution will remain, so soaking is necessary. (soaking = saving water so...)
For clothing, i only use oxiclean on heavily soiled clothing. For non-bleach powdered detergent, it's necessary. For bleached powdered detergent, it already has it for the most part (oxygen bleach that is), adding some will help as well. Of course this goes the same for liquid detergent.
Do not use it on any metals cuz it will oxidize them (rust, etc).
It does work well on bathroom stuff, but you have to make a paste, and the heat is lost so quickly that it's not very effective. The hot water increases the reaction rate and shrinks the waiting time. Let's say you want to clean some mildew, the vertical walls are pretty much not going to get cleaned fast, but the horizontal surfaces, they will get cleaned with a solution of the stuff easily. Obviously the solution wont stay on a vertical surface, so you have to make a paste which uses much more of the stuff than a solution.
The packaging says not to use boiling water. The warning is there so you dont get burned. If you have ways of working with boiling hot water without getting hurt, use that with oxiclean.
There are other brands of oxygen bleaches around, as long as it says oxygen bleach, it'd work.