Oh I misread your post a bit. Nostrudel blocks YOU from seeing them (shows them as "hidden" with an option to un-hide), but doesn't stop other people from seeing them. No client can do that because you can't control what other people see on the network, it's a pretty core part of nostr.
Discussion
I wonder if it can be done client side though, without touching the base protocol itself.
Like, the client reads from the mute list of that profile you're visiting and "soft hides" the replies in it's UI only.
Then of course if someone uses a client that doesn't support the feature they will see the muted profile replies to that note normally.