I was getting near the end of a bottle of gloopy shower gel. So in my usual tight fisted way I added some water from the shower (by squeezing the bottle and then letting it suck water in from the shower water).
To my surprise, the shower gel remained gloopy and the usual dispensed amount lathered up fine.
Bit more usage, bit more water added, still gloopy and the same dispensed amount seemed to lather up just as well.
I have concluded that the shower gel has homoeopathic properties in that it retains its functional essence through multiple dilutions.
Not perfectly, though, otherwise I could put a drop in a swimming pool and be set up with shower gel for life.
Also, I can't be arsed to capitalise on this by getting empty bottles and dilution one bottle into several because shower gel costs peanuts and life is just too short.
Cheers
Dave R