I have worked on Printer repairs for more years than I care to count, and there are 3 treatments we use in Australia.
The best is Hurst #7 roller cleaner, used widely in the printing business, but we get it in 25 litre cans, lasts years for a team of techs.
This is a local supplier, but it is obviously available where Printing machines are used. When we first got it, it was from a local Printing shop, when it was proved, went to the source.
Next is CO Cleaner, comes in spray cans, and is very good at deglazing rollers, doesn't smell like #7, is very volatile, you must be quick.
Last is Isopropyl Alcohol, Methylated Spirits will do, the least volatile, and least effective, but does work to some extent.
Hurst #7 comes with a warning, is a cancer suspect, should not be used in a closed room, but is very effective. CO Cleaner will be readily available worldwide, and is much less of a risk.
If a pickup roller is worn, it will be seen after cleaning, and must be replaced, or constant cleaning will be necessary.