In reply to homing-penguin:
Not a waste of time, IMHO, provided the face fabric hasn't weakened, the membrane isn't delaminating, and the seam tape isn't coming away.
I'd recommend the following:
i) a good wash with detergent washing powder (no conditioner)
ii) a wash with a soap cleaner to remove the detergent residues (in a spotless washing machine; read the manual about 'service wash')
iii) proprietary reproof
Toggles can be replaced cheaply.
Renovation should cost you no more than £10.