So you just open the lid to let the gas out? That seems way easier than messing with airlocks. How do you know when it's done fermenting if you're not watching bubbles in a lock? I always worry about mold getting in when you open it that often.
Honestly you just get a feel for it after a while. I check the lid once a day, listen for the hiss, and give it a quick sniff. If the bubbling has stopped for a few days and it smells right, it's usually done. Opening it that fast doesn't let much in, and the CO2 pushing out helps. The key is keeping everything super clean before it even goes in the jar.