My ultimate favorite:
"Take a warm shower, it'll make you feel better." - This is usually said by people who don't understand my terrifying fear of showers. Which is about everybody but three people.
PLUS, my depression doesn't breed on my skin, my suicidal thoughts aren't a body paint that just washes down the drain whenever I bathe. My problems are still there when I step out, and I can't just scrub at my skin until they go away. Soap is not magical, or a healing stone. In fact, you can't even eat it to clean your insides; it would just taste terrible and you'd feel sick for a very long time.