Do you think I'll have to quit my job over this?

I started a new job 3 days ago. We go to different businesses and clean them. My supervisor is training me and I was watching him clean a bathroom. He wiped down a toilet and used the same rag to wipe down the light switches around the office. I would talk to him about it but what if he brushes it off? Then I would need to report it to his supervisor but then he would know it was me. If I didn’t say anything to him but just reported it to his supervisor, he’s less likely to know its me. Im afraid if I report him he will know it was me and he’ll be a huge jerk to me or try in get me fired some other way. Should I just report him and quit? I need the job because im completely broke and that would really suck to quit.