There are loads of them, we certainly make for half a dozen or more brands. Not all are equal - I know that we get people calling up and looking to buy material at less than the cost price to us, so whoever is selling it just that cheap is knocking it out at low strength.
Another thing to note is whether you are actually comparing apples with apples. Is your bleeding fallout remover actually pH neutral? At least one mentioned here used to be quite significantly acidic, somewhat defeating the point (if you are happy with an acid, use the likes of ABC which do the same job and cost miles less).
