Maybe this could be solved a different way.
Have you considered using sponsored guest access? With this setup guests nominate someone in the company to approve their access (usually the person they are visiting). That person gets an email with a link to click on to approve that access.
https://documentation.meraki.com/MR/Encryption_and_Authentication/Sponsored_Guest
Another option I have used is pre-paid billing. With this you print out a bunch of PIN numbers on cards. You give these to reception and they give them out to guests. You don't actually bill the users though. Make sure you use the "fast pre-paid" option.
https://documentation.meraki.com/MR/MR_Splash_Page/Configuring_a_Prepaid_Card_Billing_SSID
Splash Access (a third party commercial option) also do a great guest access solution. You can print our a daily QR code (or setup a tablet to display it automatically). Guest users coming in can scan the QR code to setup the guest WiFi automatically for them. This actually uses a daily rotating PSK under the hood.
The Splash Access solution also has a million controls you can configure and customise as well.
https://www.splashaccess.com/splashaccess-guest-ambassador/