Well, certainly in any novel a whole host of rhetorical strategies are used in every chapter, but I am going to focus on chapter thirteen and how it reflects Wilde's interest in the Gothic novel. Certainly, this novel can be viewed as a more "modern" version of its predecessors, focussing as it does on the supernatural and many binary oppositions such as alive/dead and good/evil that are explored in this work. However, a key part of Gothic fiction is setting, and how eerie, supernatural and disturbing places are brought to life through imagery.
The description of the attic where Dorian is just about to show Basil his picture is no exception. Note how imagery is used to appeal to the five senses and create a setting that is foreboding in its intensity:
They walked softly, as men do instinctively at night. The lamp cast fantastic shadows on the wall and staircase. A rising wind made some of the windows rattle.
Clearly, the "fantastic shadows" combined with the onomatopoeia of the windows "rattling" serve to create a spooky atmosphere. Note too how the picture furnishes a secret lair full of damp, death and decay, and once Dorian has killed Basil, the "drip, drip, drip" of his blood is loud enough to be heard as it falls and splatters on the carpet.
So, in Chapter 13 Wilde shows why this novel is considered as a modern Gothic by the setting and atmosphere he creates, which eerily point towards the supernatural, the excessive violence within Dorian and the diabolic pact that he has made.