I bought a fancy Tamiya model cleaning brush. The big brush does not work too well, but the small tip is good for getting dust out of intricate places. I don't think it is worth it as you can achieve the same results with Q-tips or eyeglasses wipes.
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I think it is counterproductive to clean a model using bare hands as skin oils could ruin the parts you've already cleaned. For that I hold the model using some sort of barrier, it could be a napkin, handkerchief, another eyeglass wipe, or gloves. As others have mentioned, be careful with gloves. Sometimes I am lazy and still handle them with bare hands, but I wash them well first.
Car polish works marvels to revitalize old models and remove dirt stains. A lot of patience and care is needed to polish around small parts.