These air lock issues seem to come up in a few threads. It's really puzzling to me that there are some many issues and concerns.
Consider the wide variety of environments that we, as individuals and as a wide-ranging group, have.
The humidity in my cellar is current 35%, and it ranges up to 85% in the spring and fall, and the temperature ranges from high 50's F to mid-70's F. I have a dedicated environment, but it's far from consistent. I've certainly got mold and mildew in the air.
In the past I've made wine in my kitchen, a spare bedroom, and in a corner of the dining room. I've never made it in my garage, but I've pressed there. This is pretty common, and it exposes the wine to a lot of other things, including seasonal pollen.
I've had airlocks go a full year without drying out or growing a biology experiment, and I've had others do either or both in 5 weeks. I've had dry airlocks that never produced a problem, and at least one where I'm positive it's the cause of failure.
So my advice stands -- regardless of what's in the airlock, check it weekly. Swap out airlocks monthly to ensure they are clean. Swap vented bungs quarterly when adding K-meta.