Cleaning undercarriage?

I normally just spray under the car with the pressure washer as I'm cleaning it, but I'm wondering if I should start using some cleaning products on the under carriage (degreaser or foam cannon) to clean it better? Does anyone do more than just spray the underside of the car with a pressure washer, or is hitting it with a pressure washer enough? I would like to clean it like I do my wheel wells, which is spray it down with cleaner and scrub it, but the undercarriage would be tough without a lift.

 

Thanks. I have one of the electric Sun Joe pressure washers which does allow me to put soap in it, but I heard the electric pressure washers don't have enough power to use with the undercarriage washers and a gas powered one is pretty much required.

 

I seen a product called "Salt Off". I might get a sprayer and hit the undercarriage with that really well, then hit it with the pressure washer. It's supposed to break down salt then leave a protective layer. It's only like $40/gallon so worth a try.