I can't get a soap stain out, any suggestions please?

[MsAdorabelleDearheartVonLipwig]

I have a favourite cotton jersey jumper that I spilt bubble mixture all over at a friend's party. Sponged it down and put it in the wash. It now has an enormous tide mark stain all down the front of the jumper. I've washed it three times and soaked it in that crap Vanish and it won't budge.

Have I ruined it forever? It's navy and white striped so I can't bleach it.

[olbas]

Have you tried vinegar?

[MsAdorabelleDearheartVonLipwig]

No I haven't. Anything is worth a try. Thanks.