[slob]

parafin or petrol will creep under x/o/z-rings and wash out grease

1. spray wd40* on a rag, clean chain,
2. spray a LITTLE brake cleaner on another rag and wipe off wd40 residue, as that will prevent chain lube/wax adhering.
3. lube or wax chain with your prefered product

you can skip step 1 if you use a dry lube

* other penetrating sprays are available

I've found B&C Express to be very helpful and efficient