It's really the straps that get crusty. We haven't washed ours' yet after 8 months' use. But I need to ASAP because it dragged along the floor at urgent care last week. That's the one kind of contamination that freaks me out! But our Ergo is dark brown and doesn't show dirt.
Quick tip: the sucking pads seem way spendy for what they are. Instead, you can cut the feet off a pair of knee highs (or use baby legs) and thread them over the straps. You could hem the cut edge for a classier look. Personally, I use my favorite retired pair of striped socks and leave the frayed edges showing. But I'm a hippie girl with (many would say) a troubling style sense.
We switched from sling to Ergo when my daughter was about 5 months old. She could comfortable sit with her legs spread out by then.
Often bumbling mother to baby girl "Sprog"
Born November, 2009