Just to clarify, the method you're suggesting doesn't prevent the client from associating with the SSID, it only blocks browsing.
This still presents a security risk because the client will still be receiving an IP address, allowing it to scan the network.
I don't know if you've done this before, but what he actually wants is to implement MAC address filtering, so only clients on the list will be allowed to associate with the SSID.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.