If you need to use this type of tool, perhaps just don't use twitter at all.
I remember back in the day you'd expand a tweet and just see it and the responses, but now you immediately get "more tweets" below it that have nothing to do with what you're reading.
Twitter does to a certain degree do a good job of hiding replies under 'show more replies' I get the feeling that people with 5 digit and up followers do not click it, if they do, most do not go out of their way to block people.
I think you're overthinking it. Unless you're a known person who interacted with them meaningfully before, they won't even know you blocked them. If you're just blocking to clean your timeline, you're the only one who will see the effects.