Much more effective is down voting the question for lack of research, as well as not being useful for future visitors.
Next step is to verify if the question fits one of the close reasons. Often too broad or unclear are appropriate choices for these type of question. The OP will get an inbox message that their question received a close vote and once a closed a post notice will contain links to articles in the help center. Questions that are closed and down voted will be deleted by the Roomba process.
If you do know the question has an answer on Google, you might as well go the extra mile and find a duplicate that is applicable. The benefit of that option is that the OP will get their answer, hopefully notice the much better question/answers, and the post could be hammered by a gold badge holder, closing it early, preventing (low quality) answers.
If you really insist on leaving a comment, make sure you guide to user to resources that help them to improve their question. You could point them to
[ask] (see comment magic links) or verify if they found a particular post/wiki/blog/documentation and if they did, let them elaborate why the solution found there didn't work in their context. Always suggest they edit their post as some new users are so used to a thread based conversation that they never noticed the edit link under their question.
Paraphrasing what a CM once said: If you leave a comment you need to be prepared to engage in a conversation with the OP. If your only aim is to have a chuckle about your witty-ness , refrain from commenting at all.