Topic: How to clean the 3DS Screens safely without having to buy anything?

Is this possible?

I guess it is. It really depends what you are trying to clean if its finger prints and smudges you can use a soft cloth like an old t-shirt or something along those lines.

Isophoric alcohol (or "rubbing" alcohol) works good if you have some on hand, use a soft cloth or cotton ball to clean it and it should dry on its own. Isophoric alcohol is whats used in those little premoistened cleaning cloths made for eye glasses so its perfectly safe.

Your breath (exhale like you'd do on a window) and a clean lense cloth (or even the underside of your shirt) also work just fine too.

Depends on how it's dirty. I use my t-shirt with some moisture to clean everything. Never any scratches that wouldn't happen anyway... Screen protectors help, too, but I can usually avoid scratches just from normal use. So, advice from me would be not to worry about it.

spit
sleeve
rub

Never ever use any chemical cleaner to clean led/lcd panel. Just use pure water and soft cloth.