JSFiddle - React, Tailwind, and code Playground

HTML

<div id="cleanlist"/>

JavaScript

//Store PHP values.
var ci_sites = [111, 222, 333, 444];


function dobuild(){
//Store textarea input into Array, Duplicates Removed.
var text = '111 222 333 444 555 666 777 abc kjl poi sdf tyu pom bgf yui sdf uyt qdf etr hgf jkh sdg por jkh cdf cdf ùpo eri'.replace(/ /g,'\r\n'); //$("textarea#builder").val();

    
var lines = text.split(/\r\n|\s+\n|\s+\r|\n+|\r+/g); 
var lines_arr = [];
    $.each(lines,function(index, item){
        if ($.inArray(item, lines_arr) ==-1)
            lines_arr.push(item);
    });
console.dir( lines_arr);
//Remove value from ci_sites.
var A1 = lines_arr;
var A2 = ci_sites;
for (var i = 0; i<A2.length; i++) {
    var arrlen = A1.length;
    for (var j = 0; j<arrlen; j++) {
        if (A2[i] == A1[j]) {
            A1 = A1.slice(0, j).concat(A1.slice(j+1, arrlen));
        }
    }
}

//Chunk The Array Into Sets Of 50.
var cleaned = A1;
var chunk = [];
var arraySize = 50;
for (var i = 0; i < Math.ceil(cleaned.length/arraySize); i++) {
    chunk.push(cleaned.slice(i*arraySize,i*arraySize+arraySize).join(';') );
    var chunkbr = chunk.join("<br>");
    $("#cleanlist").append("<p>i=" + i + " Cleaned CI's:<br><span style='color:#f00'>"+chunkbr+"</span></p>");
    }
}

dobuild();