How can I get stains out of white canvas trainers?

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I have a white pair of partial canvas dc's. Iv used a brush, tried washing powder, baking soda etc and although they are obviously cleaner I can't get some stains from them?

I don't want to put them through the washing machine as the insides are bright blue and around the trim and I worry it will run!

When I have bicolour clothes with stains on he white part I use bleach applied with a cotton swap. Just wet the tip in pure bleach and very lightly apply on the spot. Leave 5 min and rinse with a cloth.
Not sure if it could work here if inside it blue... caution is advised

I read you shouldn't use bleach as it dissolves the glue used in trainers? They look rubbish today! Like a dirty grey!