Slack doesn't provide an easy way to clear general channel history

clearSlack.js

// 1) Install this plugin:
// https://chrome.google.com/webstore/detail/custom-javascript-for-web/poakhlngfciodnhlhhgnaaelnpjljija/related?hl=en

// 2) Go to this page:
// https://my.slack.com/archives/general

// 3) Use this code:

setTimeout(function() {
   $('.moscow_red.cursor_pointer').click()
   setTimeout(function() {
     $('#batch_delete_div .cursor_pointer')[0].click()
   }, 50);
   setTimeout(function(){
     $('.btn_danger').click()
   }, 150);
   setTimeout(function(){
     $('.dialog_go').click()
   }, 350);
   $('.generic_dialog').on('hidden.bs.modal', function (e) {
       location.reload();
   })
}, 3000);

// 4) Leave the tab open and go do something else for a while...