I followed your link to the comment on your old post and the link the commenter offered
http://www.cockeyed.com/inside…
, which specified a much more dilute ratio of soap to water, mentioned a manufacturer’s warning that reuse could result in contamination and under the heading “Update” reports “slime” growing in the post author’s dispenser after some months of reuse. I suspect there’s a lot less risk of that with the 60% soap mixture you proposed, although with the biodegradable (“bio-delicious”) soaps that recycle-minded folks are liable to use, it might remain an issue—especially if the water floats on the soap as in the photo on that Web page, because it’s the zones of water with dilute soap in which soap-eating bacteria can dine with impunity and flourish into a robust slime you’ll never get rid of short of a long boil. I don’t know that soap-eating bacteria including any strains that cause disease in people, only that people must not like the thought of bacteria in their soap, or else soap makers wouldn’t offer those “antibacterial” soaps with antibiotics in them (soap is inherently antibiotic, so long as it’s concentrated, but largely hand-washing is about dislodging bacteria and sending them into the sewers, not to kill them).

As the original commentator, and long-time foamy soap user, I continue to use the less-rich mixture (somewhere around 8 to 1) without any slimy side-effects. I tried richer mixtures, but found they did not produce good foam (plus it cost more!). I use Dial-brand soap refills (the giant bottle I buy at Costco lasts at least a year), which are anti-bacterial, so I would think the soap would be self-desliming. You can also rinse them out at refill time.

A few more notes:
not all dispensers are of equal quality. The very common ones with the flat back on the pump head are not nearly as reliable as the less-common ones with the rounded back (I’ve found Dial-brand dispensers of both types). The method brand one shown in Peter’s post is the good model.

My first foray into foamy soap was the purchase of a dispenser from The Pampered Chef. It had a soap pour line on the bottom, which was a 10 to 1 ratio (I am deriving this from their claim that the soap “lasts ten times longer”), nowhere near the 60 percent ratio that Peter uses. Here’s the product link: https://www.thepamperedchef.com/ordering/prod_details.tpc?prodId=3745&words=soap
Their price is exorbitant at $14. I can get a Dial foamy soap dispenser, complete with soap, on sale for around $2.50. I also found The Pampered Chef product too tall and skinny — it tended to tip over. The Dial bottles are much more stable.

A nurse at this link:
http://www.thriftyfun.com/tf256139.tip.html
says that a few drops of bleach will obviate any fears of bacterial contamination, which she attributes to fear-mongering soap vendors worried about a drop in sales due to soap dilution.

Here’s a good link about debugging problems with your foamy soap dispenser:
http://www.forsoapmakers.com/foam-pump-bottle-info.html

Here’s someone who recommends a 3 to 1 H₂0 to soap ratio. You will note in the photo that she is using the better-quality rounded pump heads.
http://www.heartsandhome.com/hearts/2008/02/frugal-foam-soap.html. She also recommends using warm water (easier to mix) and not shaking the bottle to mix.

Finally, this link will show you how much money you can save:
http://hubpages.com/hub/Frugal-Ways-Making-Foam-Hand-Soap-For-Pennies
They recommend adding 3 tablespoons of liquid soap to a Dial bottle, and filling with cold or warm water.

In our case, the monetary benefits are secondary. We prefer foamy soap, finding it is more fun, less messy, and provides better coverage. I would like to believe that this results in cleaner, more germ-free hands.

I’m interested to try, but I can’t tell: Are these dispensers different than traditional pump dispensers for soft soap and hand lotion? I wonder if they a have narrower siphon tube or anything more elaborate about them.

Oh. Never mind, I guess. I followed Derekmac’s link and read that they’re special and patented.
http://www.forsoapmakers.com/s…

Actually, that same site that Derekmac points to has a page devoted to re-use of the bottles:
http://www.forsoapmakers.com/f…

I would suggest distilled water as another measure to avoid the nasty bacteria.

City tap water ought to have some residual chlorine in it, which I think would make it better than distilled, by giving some protection. The contamination risk isn’t from the water per se butfrom opening the bottle for refilling, during which time bacteria from the air or your hands, perhaps via the water, get in and get to grow in that usually stagnant water. If you just open a new jug of distilled water to the air for some minutes some place other than a chip manufacturer’s clean room, and then leave to sit at room temperature, it will eventually grow foggy with bacteria—and algae, if you give it light. Pasteur showed this.

Actually, if you’re willing to wait a few years, I suppose you might not even need to open the distilled water you buy at a store, since it’s not advertised as sterile.

I have been using dial soap for years, the orginal aroma. Latley I have found that the orgianl aroma has changed. Dial soap has always comforted me. I have been going through a very bad time in my life right now. But I just smell dial soap and it comforts me. I know that kind of sounds real strange but when I was young and felt really bad about myself I had a neighbor who would comfort me and he smelled of dial soap. So now when I feel bad I just wash my face with the orginal dial soap and I feel so much better. If you want the whole story just let me know.

You have somehow changed the orginal smell of the soap. Well I am not happy. If you have an overstock of the orginal soap, please let me know and I will buy some.

Thanks for all the wonderful years of your wonderful product.