Creating a wired guest network using a second router

I have a fairly generic home network setup consisting of a single router currently configured with a wired connection to my primary computer and guest wifi to devices that I only want to have internet access. I need to add another computer to the network but it needs to be wired and guest internet access only.

The following is what I found online as a possible solution using a second router. Can anyone comment on this setup and if there are security risks that are overlooked?

"To create a separate, wired guest network with a second router, connect a LAN port on your primary router to the WAN/Internet port of the second router, disable DHCP on the second router and then configure the second router to act as a separate network. Ensure the second router uses a different subnet (like 192.168.2.x if the first is 192.168.1.x) to avoid conflicts and provide internet access to devices plugged into its LAN ports, while keeping them isolated from your main network."