
It is so long since I used clippers for only 1 or 2 dogs I cant remember, but as my blades go anything from 1 to 6 months doing all my bunsh and the "visiting client dogs" it could be ages before yours need attention. As you have said you are cleaning and oiling after each use, and only using them on clean coat, you are doing all that is best for you blades. You will tell when they are losing their edge as they stop sliding through the coat so easily.
bye
Gwen