I understand, being forced to look at AIDS makes me not want to come here. If you have a userscript plugin like Violentmonkey, you can use this (it works in overboard too):

// ==UserScript==
// @name heyuri
// @namespace filterstuff
// @include *.heyuri.net/*
// @version 1
// @grant none
// @run-at document-end
// ==/UserScript==

{
// Get board name from the current URL!
let board = document.location.pathname.substring(1, document.location.pathname.indexOf("/",1));

// Get filters from the browser's local storage!
let filters = localStorage.getItem("filters");
try {
filters = JSON.parse(filters);
} catch (e) {}

// Fix the variable if it's invalid!
if (!filters || typeof filters !== "object") filters = {};

// Make sure the filters object has an array for this board!
if (!filters[board]) filters[board] = [];

function hide (event) {
// If didn't click with the left mouse button, don't do anything!
if (event.button !== 0) return;
// Prevent the click from doing anything else by accident!
event.stopPropagation();
// Add this post number into the filters!
let num = Number(this.dataset.num);
filters[board].push(num);
localStorage.setItem("filters", JSON.stringify(filters));
// Hide the post!
let post = this.parentNode.parentNode;
if (post.classList.contains("op")) {
post.parentNode.style.display = "none";
}
else {
post.style.display = "none";
}
}

// Loop through threads on the page!
let posts = document.getElementsByClassName("post");
for (let post of posts) {
// Get post number from the ID!
let num = Number(post.id.replace(/[^0-9]/g,''));
// Hide this post if it was filtered in the past!
if (filters[board].includes(num)) {
// If this post is OP, hide the entire thread!
if (post.classList.contains("op")) {
post.parentNode.style.display = "none";
}
else {
post.style.display = "none";
}
}
// Add button for hiding the post!
let button = document.createElement("a");
button.innerHTML = "[Hide]";
button.style.cursor = "pointer";
button.dataset.num = num;
button.addEventListener("click", hide);
post.getElementsByClassName("postinfo")[0].append(button);
}
}