Using an oil based pomade can be slightly intimidating because most of us use water based products for the majority of our lives. If you've tried it, whats likely is that you've used Murray's which in terms of a performing hair product works extremely well. I've had some of the best hairstyles using Murray's pomade, but the washout was just terrible and made me not want to use it after a while. Advancing to more user friendly homebrew oil based pomades improved the washout experience, but it was definitely still a tough thing to do. This was all up until I used a shampoo bar.
A shampoo bar is exactly what it sounds like, a solid form of shampoo. It's typically made with a variety of oils which bind to lye making it a solid form and will not contain chemicals typically found in normal liquid based shampoo. The benefit of this is you can take the bar and apply it directly to your hair and scalp and literally scrub out the oil based pomade layer by layer. You'll notice the top layer will take a few scrubs, and when all the pomade is out you'll advance down to the mid-layer then eventually down to your scalp. The process happens very quickly, I can typically get all of the product out in 20 seconds or less. This is much different than normal shampoo which can take multiple applications and constant scrubbing with my fingers. That experience can take around 60 seconds or less depending on the amount of build-up.
When it comes to recommending a product its a bit difficult because I've had success with every shampoo bar I've ever used and they usually come from the local Sprouts or Whole Foods. If you don't have access to a store like that in your area, here are some other recommended products you can try.