cleaning gritty surface noise on LPs

I'm afraid you will not be able to fix these records. Cleaning, as you have already noted, does nothing. Somewhere down the line something happened to them, maybe played with a bad stylus. In a last ditch effort, incase somebody sprayed them with contact cement, you can spray them off with brake cleaning fluid. It will not damage the record, I have done it to prove a point.

The best approach will be to buy new copies of the music you cherish.

Ultrasonic cleaning is a fad and the process has extreme limitations.  

@eryoung2k 

Unless you have an industrial clean room in your house using any vinyl cleaning method that uses an evaporative drying technique, air or fan simply re-contaminates the record with the crap floating around in the air. Records have to be vacuum dried which is why so many machines do this. The companies that rely on air of fan drying need to take a class in environmental science. So, if you are going to try cleaning your records ultrasonically you also have to buy a machine to vacuum dry them. This is an expensive messy process and a royal PITA. While you are trying to dry one side the other is being contaminated dripping all over your machine. Machines like the Nessie effectively clean one side at a time and vacuum dry it immediately then you flip to the other side. If time is a consideration, which it is for me, get a Clearaudio Double Matrix Sonic Pro which is handily the best vinyl cleaning device on the market as it cleans and vacuum dries both sides at the same time. 3 minutes and you have a clean record. 

I repeat ultrasonic cleaning of vinyl is a silly proposition. It is great for Jewelry. Have fun wasting your time and contaminating your records. 

@dogberry 

All you have to do is use the Loricraft, a fine brush and a good fluid. What you are doing is exactly as I described. However, being a very impatient person, the single most important factor in record cleaning is spending as little time as possible doing it. I know the Double Matrix is expensive, but IMHO worth every cent because of the time it saves doing the best job possible. 

@eryoung2k 

You are right, I am a very snarky person.

Happy Black Friday. I suggest you hide the credit cards:-)