I wouldn't leave wax on thick and cloudy w/o testing it first. That's for two reasons. Car wax when left on can harden and be really hard to remove. You can also see this on furniture or a hard wood floor, if you've missed a spot the last time you waxed. Secondly, I've been told that many waxes need to be buffed to obtain a hard uniform coat that provides protection. That's why two light coats of waxed buffed are better than one thick one. If you want to leave it messy, I'd stick with an oil like mineral oil. Renwax is a good protectant, but it won't stop brass from oxidizing, however neither will oil. You are correct that a dry environment is the best protection.