Foaming Soap:
Here is a link with information, tips and resources on making soap
for foam soap dispensers.
http://www.forsoapmakers.com/foam-pump-bottle-info.html
Some of the information from this link is:
Foam Pump Bottles
The bottles are designed to work with a thin substance of water-like
consistency. It must have sufficient surfactants (soap or detergents)
to create the foam. The liquid should be water-based, and it has to
be able to foam using only normal air (no gasses or other
propellants).
Many commercial soft or liquid soaps will work in the foam pump
bottles if sufficiently diluted. However, those soaps that contain
thickeners may not work as well because they need to be so greatly
diluted to counteract the thickener and be thin enough for the pump
that the soap itself becomes to diluted to make good foam.
Handmade liquid soaps usually work extremely well in the foam pump
bottles as they are generally thin to start with and normally do not
contain added fillers and thickeners. Do not use "melted down" bar
soap in place of an actual liquid soap because bar soaps tend to
clump or gel and can clog the mechanisms inside the foam pump.
Dilution Rate
The goal in determining your dilution rate is to find the most you
can dilute the product and still have the desired feel of the foam.
As a general guideline, you should be able to dilute your normal
liquid soap by 3 - 6 times.
Start with 1 part soap and 3 parts water, and add additional water
(if you want) until the soap foam thins a little bit. That will tell
you how much of that particular type of soap to use.