I used to own a VPI machine… the big one. It died a couple years ago and I bought a Nessie… a way better, quieter, more sophisticated machine that I think does a better job. I have many albums I bought from the 60’s and 70’s that cleaned up perfectly despite their incredible abuse. Then there is one in forty or fifty that is noisy… and cleaning just does nothing. Occasionally it is a new album. I think this is the observation the OP and a couple other folks here made as well.
I have not used an ultrasonic, but my Nessie is good and I suspect… but have no proof whatsoever that running these through an ultrasonic would not clean them up much better. I would love someone here to say I am wrong… and that x-brand will clean them up. I would definitely put that machine on my list to use in the case where my normal machine fails.