If you are looking to refill any sort of toner, you will need the
correct toner that goes with that machine. In other words, there is no
magic universal toner, each laser printer has it's own formulation.
(Yes, yes, I know you can buy universal toner but it is rubbish, don't
even bother). This is compounded by having a color laser printer where
you need 4 different toners, and the formulas are very very complex.
The best aftermarket toner available is from Static Control, who spends
tens of millions of dollars a year on R & D and are leaders in this
field. If you go to their product page and they have refill toner for
your machine, you know there is a quality product available that has
been thoroughly tested and works.
Here is the link:
http://www.scc-inc.com/Products/
Unfortunately the OKI C5250 is not listed so unless someone else has a
source of toner for it they would like to share, you will have to buy
genuine.
James Sodor
www.whatcartridge.com