Can I just add that the business of being able to grab 2 things (one in each hand) is more to do with old type "supplementary earth bonding".
Supp bonding may still apply in older installations. Under the latest regs, it's not needed.
This is a complicated and potentially hazardous area, which makes it so important that professional help is essential here. I promise you that, even "proper" electricians like my friend Bright Spark, have scratched their heads a few times to interpret the regs.