White shirt. Yellow sweat stains, removal tips please

[Singlebutmarried]

As above really

DH is anrather oily and sweaty beast and his shirts get very stained in the pits.

I’ve tried vanish, vinegar and one of the whitening sachet things (the whitening sachet has lifted the stain slightly but not eradicated it)

Does anyone have any other suggestions.

I use this on my DHs fragrant 🤢 work shirts
And it's made such a difference
www.dr-beckmann.co.uk/product/stain-devils-antiperspirant-sweat-marks-250ml/

Its definitely saved a few shirts from the bin and I use it on them all the time now and it stops the build up of smell and marks

Thanks.
That’s the same brand as the whitener I’ve just used so will pick some of that up next.

If you live near a Lidl, they currently sell that Dr Beckmann spray.