De or het doorspoeling?

The correct Dutch article is:

de doorspoeling

Rule Words ending in -ing: almost always de. See the rule

How to use doorspoeling

the doorspoelingde doorspoeling
this doorspoelingdeze doorspoeling
that doorspoelingdie doorspoeling
our doorspoelingonze doorspoeling
your doorspoelingjouw doorspoeling
every doorspoelingelke doorspoeling
which doorspoeling?welke doorspoeling?
a big doorspoeling / the big doorspoelingeen grote doorspoeling, de grote doorspoeling