Replacement parts available here.

There are lots of good recipes on the internet for home made foaming soap, and they are all pretty similar.

Use somewhere between a 1:4 and 1:6 ratio of soap:water. Any liquid soap will work, but castile soap works well.
Add the soap and water to your jar. Warm water will mix easier. Stir to combine, or use a storage lid and shake. Add a few drops of essential oils if you want to.
Screw the lid with the pump onto the jar.
Enjoy the luxurious foam!

Pint and quart jars work well. The pump mechanism plus straw is about 6" long, which means it comes to about one inch from the bottom of a quart jar.

For best results, cut the tube so that it does not touch the bottom of your jar. 

They are made of stainless steel and plastic. The satin finish looks like a natural or brushed stainless steel. The charcoal black and oil rubbed bronze are painted stainless steel. 

We also carry a variety of different colors and styles of regular (non-foaming) soap pumps for Mason jars, so you are sure to find the perfect one!

Troubleshooting:

First, there may be some water built up in the air chamber in the pump (this is the plastic housing that contains the spring). To expel any water from the chamber, you can hold the pump upside down and squirt it a few times. There may also just be some build-up in the pump itself which can typically be cleared by dispensing hot water through your pump until clean water is coming out.

If that doesn't seem to be enough, you may need to remove and clean the aeration filter itself. This is a small cylindrical piece that can be accessed by pulling the pump head up and off the base. This can either be rinsed with warm water or soaked in a mixture of warm water, baking soda, and vinegar to remove anything stubborn. You can buy a replacement filter here.