Yeah, if you're cleaning records that were likely involved in a few Pizza Parties, quite trashed thrift finds, you can't expect a quick one step process doing much.
As mentioned, no brush gets in the groove, and concur, a CF Anti-Static Brush is the wrong tool for the job at hand. Get the right stuff needed for wet cleaning.
Osage, MOFI, Disc Doctor are better choices for brushes to spread-massage cleaners-rinses.
No harm-foul to repeat a cleaning process, or to use a multi-step process. Always do a final pure water rinse.

