Or you can try this.
https://www.amazon.com/Parts-Express-Non-Inductive-Dummy-Resistor/dp/B0002KRDGC
They’re quite inductive. I know, I tried them.
Other than tubes which may need time to de-gas and new speakers which need to loosen up, burn-in is mostly nonsense. Definitely nonsense for cables.
For electronics, leave on for 24 hours. Playing doesn’t do diddly.
Why mono? Please explain the electrical reason behind it