I use wet sponge, but with distilled water. I do not have positive confirmation for my suspicion, but I always thought that people who complain of wet sponges ruining their tips were using tap water, which will result in a layer of mineral deposits building up on the tips. Distilled water obviously won't have that problem, when it boils off nothing is left behind, so I don't see how it can ruin a tip if it leaves nothing behind.
I bought a used Metcal solder station for my home bench about 20 years ago because the ones at work seemed pretty bullet proof, and both the power base and the three size tips I regularly use are all still working great after 20 years. I'm not sure what modern Metcal gear is like because I've never needed to replace mine. Hopefully they have maintained the same level of quality.