I've used silver markers as well but found the result is not strong/durable enough. These MOLOTOW markers seem to do a good trick but I found a video showing some result, and I'm not impressed anymore.... results are shiny but dull....dimm, can't find the correct word.... in any way not "mirror" like enough.
Found this video that shows the result of a spraycan cap being chromed: https://youtu.be/mqZgAy6kRG0