Actually, a wet sponge can shock and crack a hot tip over time. A lot of people use brass wool instead, it cleans without the sudden cool down. Abby_brown's story about the tip going bad fast is a perfect example of how that happens. Constant wet sponge use just speeds up the damage on cheaper irons. You want to keep the tip tinned with solder, not just wipe it clean.

Tell me about that sandy soil job.

Read a blog that called internal links the site's own recommendation engine.