I've used the Vanish stick and it doesn't work. A scoop of Vanish in the wash leaves clothes like cardboard. Normally, I would pretreat with detergent and leave for 15 mins before putting it in the wash, but NOTHING gets rid of toddler food!
I soak the worst stuff in biological powder and soda crystals. then wash at max 40 with bio powder and again soda crystals (I use half a scoop each). hanging outside to use the uv light for bleaching also helps.