allLikesDelete.js

(function allLikesDelete() {
    var likeNodes = document.querySelectorAll('.my_like'),
        length = likeNodes.length,
        i = 0,
        timeOut = 600; // ms

    function likeDelete() {
        likeNodes[i].parentNode.onclick({});

        if(i < length - 1) {
            setTimeout(function(){ likeDelete(); i++; }, timeOut)
        } else {
            setTimeout(allLikesDelete, timeOut);
        }
    }

    likeDelete();
}());