In reply to Reach>Talent:
You’ll probably have to redo the DWR (If it’s a large area) with grangers or Nikwax.
I imagine alternating passes of WD40 and then detergent (washing up liquid) and warm water (forming an emulsion) would work, and be safest.
If that fails you could try a small amount of isopropyl alcohol, or uncoloured methylated spirit (Eg. Surgical spirit sold in pharmacy).
I have successfully removed bike chain oil and pen biro using one or the other of these methods from my gortex mammut jacket.
Post edited at 13:21