I'd recommend any vacuum based cleaner. I had a VPI 16.5 and found a new Clear Audio Smart matrix on A'gon for $500. I sold my VPI for $400.
The Clear Audio is built better and quieter than the 16.5, but still noisy. It's bidirectional also.
Both machines achieve the same goal equally, I just like the build quality on the Clear Audio better. The reason I think the vacuum is necessary, is to remove all the crud to a separate tank with force, not just rinsing.