For gas meters I made a 3D printed mount for a hall effect sensor
I do have the Honeywell probe operating in the water meter. I filtered the signal with a low pass filter based on: max flow rate of the meter in litres per second / litres per pulse = max frequency. According to ELS10139-V100-Brochure-V2-INT-English.pdf the max flow rate for their largest 40mm meter is 20 m3/h (~5.6L/s). 5.6 L/s / 5 L/pulse = max 1.12 pulses per second (Hz). Then create a RC low pass filter for at least twice this frequency. I think I ended up using 1uF and 10k for a cut off frequency of ~15Hz.
You can use this site for easy calculations for low pass filters.
Low Pass Filter Calculator
With this setup I have not had any debounce issues