ultrasonic cleaning is the best way to dig contaminants from deep in the groove
UT cleaning is but one way to clean a record. As the book says Chapter XII about the manual-sink process that uses 3 chemicals with one being a weak acid, The incorporation of the acid chemistry does manually what ultrasonics can do with power; their convenience notwithstanding. But the book in the Forward also states: All cleaning procedures specified herein are presented as only “a” way to clean a record. No claim is made there is only one way to approach the process. In the final analysis, the best cleaning process is the one that is best for you.
I also think static charges are created in the groove when it is rubbed by a diamond stylus.
In the book (Chapter VI) it states: The article Phonograph Reproduction 1978, James H. Kogen, Audio Magazine May 1978 (Audio-1978-05.pdf) goes into some detail on static; what causes it and what does not – the needle in the groove was not a source of static. The article indicates that static is not uniform, but exists as islands on a record. Additionally, once the static gets high enough to discharge to the cartridge it only reduces to about 4200 volts. A static charge on the record of 4200 volts will not create noise by itself, but it can by electrostatic attractive forces cause a transient increase in cartridge VTF as much as 0.375 grams leading to distortion and premature wear. So, managing static has many benefits.
The book also addresses the shortcomings of anti-static brushes such as carbon fiber and Thunderon, as follows: How effective are conductive brushes in removing static – only partially effective. In the paper SealezeTM SSG515AT2D Static Dissipation Brush Performance in an Operational Environment (Microsoft Word - SEALEZE_WHITE_PAPER_Final dam.doc) Thunderon™ bristles in a grounded metal frame were only able to reduce the static charge developed during a plastic film manufacture to about 4000 volts whereas the brush with an ionizing device was able to reduce the static charge to less than 300 volts. As previously stated, reducing the static to 4000 volts will be sufficient to prevent static inducted noise, but not enough to prevent affecting the VTF.