Any suggestions?

Swarfega has been suggested

Muc Off degreaser in a can and a microfibre cloth

Not from clothing, but from porous stone got oil out using pets at home chinchilla dust. It just soaked it all up, to be vacc’ed up after. Presume then a detergent could be used to emulsify the rest?

I’ve used Stain Devils before to remove grease from clothing:

http://www.ebay.co.uk/itm/Dr-Beckmann-Stain-Devils-Remover-Grease-Lubricant-Paint-50ml-/172067899160?hash=item28100bc718:g:6ZEAAOSwBLlVbu9h

Brake cleaner and rag, but try somewhere discreet first

Fairy liquid.. Or Ecover washing up liquid. A few spots to cover the grease, scrub a bit. Rinse (a fair bit). Easy.

If you use the spray degreaser then you only need to rinse with fresh water.
Theres not loads of detergent to try and get rid of which then affects the down.
Use it loads on my Rab/Columbia kit and on the bike kit – always seems to happen hanging them up so takes seconds to sort.