Your suggestion is entirely missing the point. In this context, “blocking” means stopping anything from that instance from showing up in the feed when you view “All” from your home instance, not stopping yourself from navigating your web browser to that other instance.
Find the hosts file on your machine. Add a line for the domain you want to block, like so:
lemmy.annoyingassholes.com 0.0.0.0
If that didn’t make sense, google the terms I used and you’ll find tons of tutorials.
Your suggestion is entirely missing the point. In this context, “blocking” means stopping anything from that instance from showing up in the feed when you view “All” from your home instance, not stopping yourself from navigating your web browser to that other instance.