If you do that, your in-text citation will be incomplete. Plus, if it's a direct quote there should be a page number (if available). If I was marking your essay, I'd certainly notice and the % for referencing would reflect this.
Unfortunately removing "et. al.," would make the citation invalid, as it would be implying there was only a single author, so it's important to include! I'd recommend looking through your essay/report and seeing if there are any filler words you can cut or sentences you can reword to reduce your word count as most mark schemes include a certain % for correct referencing.
It may be worth double checking the referencing format that your university/lecturer wants. In my biochemistry course at Lancaster I am asked to use Harvard referencing with in text citations in the format you showed above, however, one lecturer allowed us to use superscript numbers, like on Wikipedia, if we preferred, so our in text citations could use less words (but this has only happened to me once).
I hope I could help! Rebecca (Lancaster Student Ambassador)