Interesting product...that said, I know of no one who is using it so you may be the guinea pig. After using if for a few months, come back and post your results. We have the one that uses table salt and like it a lot.
In answer to your question: No...pressure is pressure. What you experience at the tap/shower is FLOW. Pressure regulators regulate the amount of pressure coming into your coach. Other things regulate the flow. i.e. flow rings in your shower head, screens in your faucets etc. Make sure all the screens are clean including the one where your fresh water connects to your coach. Remove the flow restrictor in your shower head.....Dennis