If your foam pump bottle gets clogged up, it could be due to small tiny particles that got caught on the small mesh screen within the foam pump head. Or, if you have not been using the pump frequently, liquid soap may gradually gel up and form a film on the mesh screen causing the clog as well.
Here is how you can unclog your foam pump bottle.
Click picture to enlarge.
You may find that when using soap nut liquid with foam pump bottle, the bottle tends to get clogged up quite easily. It is due most likely to the tiny residue in the soap nut liquid that gets stuck at the mesh screen. That is why it is important to filter soap nut liquid as fine as you can. I use a fine coffee filter paper to help me with that.
Secondly, the nature of soap nut liquid is not as smooth as liquid soap. Instead, it has more ‘friction’ in the water. This would cause the friction within the pump head over a period of time and it will not bounce back as smoothly as usual. This is based on my own observation. If you love to use soap nut foam, then perhaps you might need to unclog your foam pump bottle more frequently. A possible suggestion to help with this issue is to add in one or two tablespoon of liquid soap such as Dr Bronner’s liquid soap into soap nut liquid to lubricate the spring at the neck for it to work better.
If you are using diluted liquid soap with the bottle, you will find that foam pump bottle works very well to dispense smooth creamy foam.