As per my knowledge Bank transfer and cash deposit cannot be chargeback very soon until you dont give a written letter and give the proof, because if you are legit then you can also prove that the cash or bank transfer you received are genuine then he will get imprison for wrongly doing chargeback.

I have been using Localbicoins.com site for long time , i use to buy and sell and till now i did not got any problem, and even their escrow system is very good. Only if you are dealing with cash wallet like paypal you can beaware as that can be chargeback very soon or later also.