The carbonator cap method that is shown on Kai's website is a good way to go. You can dissolve a lot of chalk into a volume of water that way.
One thing that the website mentions that you shouldn't do is add chalk (or any alkalinity source) to sparging water. Sparging water MUST have low alkalinity to reduce the potential for leaching tannins from the grist. We use pH goals for sparging water, but that is just an indirect indicator of alkalinity reduction that is the real result. If you use RO or distilled water, you don't have to adjust its pH for use as sparging water since its alkalinity is already low.