Vanish works for me though it isn't eco friendly! I treat the stain asap with a vanish bar and cold water and then wash at usual temp. My DD self feeds and is also very messy. When we're at home I've resorted to stripping her off before her lunch down to her vest or nappy depending on the temp. I just pop a bib on which I obviously don't mind getting stained! It was getting to the point where I was having to change her outfit after every meal.
The thing is that her nappies cost more than most of her clothes
I generally change her after every meal as well, though we do have some eating suits from Hippychick for when we're out and about (and for creating general hilarity amongst the public). I am a bit too lazy to wash them very often either though
I've been doing some searches and Vanish seems to get the MN thumbs-up, so may give that a go. I've been washing at 60 for a while now - yeep!