I understood the basics of what you want to achieve.
The thread I linked you to is about a device that’s an ESP8266 processor with a relay, a push button switch and an LED.
It’s capable of being programmed with Blynk code like an Arduino.
A push button switch is the best option for your situation, as it makes writing the code much easier. With a push button switch you need to deal with “switch bounce” which is where the contacts might make and break the circuit many times in a fraction of a second when the button is being pressed or released. The code in the project I linked to has a switch debounce routine in it.
With Blynk you need to use a timer to sample the status of each switch multiple times per second to see if it’s been pressed or not. My code does this, but just for one switch.
What my code doesn’t do is to incorporate any routines to prevent Blynk from blocking the code flow if there is no internet connection. I made this clear in the write-up, but the forum has some good examples of how to work around this.
You might want to take a look at these two threads where @zodiac has take the mains power strip to a new level:
I don’t think there are any code examples here, but there’s is some interesting reading for someone’s who’s about to make a similar project.
Pete.