This is correct.
The CR Spotless Water Filter System works great BUT it's ONLY for the rinse step.
This product also comes with a spray head that has a SHOWER setting and this is key to using the filter. The Shower setting is a low volume setting and this causes the water to MOVE through the filters s-l-o-w-l-y and this enables the resin pellets to filter out the minerals and other contaminants.
If you were to PUSH water through the filter system too fast, then it defeats the purpose of using the filter because the resin pellets won't have enough time to do their job.