The best cleaner for toner is (or perhaps we should say, “was”) the old-style solvent called 1,1,1-trichloroethane, also known as TCA. It just lifted toner away marvelously. But, since 1,1,1 is an ozone-depleting solvent, you’re not going to find much of it around any more.
As a replacement, try Stencil, Squeegee and Misprint Cleaner – ScreenClean™ (#MCC-CDI). It was formulated as an ink remover. It is excellent for cleaning the inside of printers and is generally plastic-safe. It dries slowly which gives you longer tack-time for cleaning. It is not quite as good on toner as 1,1,1-TCA used to be, but they’re better than anything else we have found so far.
ScreenClean™ is available in presaturated wipes and in bulk packaging (one gallon/3.9 liters; five gallons/nineteen liters, and 55 gallons/200 liters).
The MicroCare Stencil, Squeegee and Misprint Cleaner is packaged as a presaturated wipe