I think these standard soap dispensers deliver way too much soap per push. Therefore I made this collar to clip around the neck of the dispenser bottle. I know this is dependent on the individual bottle type, but after having done a few experiments with the bottle type we have, I would say that you get plenty soap if you push it just 3-4 mm down, in stead of the 15 mm travel a "normal" push has.

Update20180205: Uploaded two screenshot of the editing process.