I doubt any veteran would say so. Not in Brazil, not anywhere. I guess the question is what "knowing someone" means.
@Shax, you are not a newbie. To summarize the info @Xclay wisely advise you to research, I would say:
If you are going to bring anyone to your place, the safest options are the GPs. In my opinion, this is an option safer than hooking up in Grindr for free and bringing someone to your place
I find both, sauna and online GPs to be reliable and reasonably safe to bring to your place. However, the sauna boys have a remarkable advantage: you can "know" them before bringing them to your place. About online boys, they often have their own place. You can start there and, once you "know" them, you can bring them to your nest.
The safest option is not hiring for over nights. Brazilians are great company for multiple hours contracts, hire them during the day. Needless to say, do not fall asleep with any for free Grindr hook up. Sleep alone in your place. I think this single rule would save 90% of safety incidents.
If you are bringing anyone to your place, keep any valuables safe and out of sight.
Do not tell that you are visiting for a few days. Tell that you are going to be there for a few months.
Those are the main tips, I think. But of course the best one is @Xclay: research the related threads.