Stains not coming out at dry cleaners, what else can I try?

[alarkaspree]

I have a red dress with black stains on it - I have no idea what they are, or how they got there. It's been to the cleaners but came back with a note on it saying they couldn't get the stains out without causing damage to the colour or fabric.

The care instructions say 'do not wash' but at this point the dress is unwearable anyway so I'm willing to take risks with it. Does anyone have any ideas about what I could try?

The fabric is 80% hemp (!), 20% viscose.

Thanks!

I've had success with lemon juice - just squeeze some on the stain and leave for a while before washing out - but on light coloured clothes. Not sure if this would bleach the red?

Thanks so much touser. I will try it. It may bleach the red but I will never wear it again as it is, so makes no difference really. If it works I will let you know!

If it is unwearable at the mo chuck it in the machine with some powder and hope for the best!