Record Research stylus cleaner will make an immediate audible improvement the first time you use it. You may benefit from cleaning as often as every one or two sides of LP play, this obviously dependant on the condition of the records.
The best way to clean a really dirty stylus is either a battery powered vibrating tool ( Audioquest made the one I own ), or the dense pile stylus brush made by the Last Company. Saturate the pile with the RR fluid and clean thoroughly. You may leave the vibrating tool in place and simply cue the stylus down onto the surface for a few seconds. To use the Last brush, go ONLY from rear to front with gentle strokes, or you will break the cantilever.
After the initial cleaning the brush provided in the Record Research bottle should be sufficient, unless you go too many plays before touch up.