removeVowels.js

function textNodesUnder(el){
  var n, a=[], walk=document.createTreeWalker(el,NodeFilter.SHOW_TEXT,null,false);
  while(n=walk.nextNode()) a.push(n);
  return a;
}
function removeText(text) {
return 'ауоыиэяюёе'.split('').reduce((acc, i) => acc.replace(RegExp(i,'gi'), ''),text)
}
textNodesUnder(document.body).forEach(i => i.replaceWith(removeText(i.wholeText)))