How to use two different sets of mailer templates for two different Devise models?

I'm using Resque to send Devise emails. To do so I set:

devise.rb

config.mailer = "Mailers::Devise::DeviseMailer"

But I have 2 devise models -- User and Client. I want to send
different devise mailer templates for each.

devise.rb says "The first four configuration values can also be set
straight in your models.", and config.mailer is one of those first
four, but I'm not sure how to set that in the model directly.

How can I do this?