I used to swap from Pencil to fan, fan to pencil and back again. Every month. I then settled on Gardiner fans but on full. Had quite a few duff ones though.
Always on full. I use less water on fans because its quicker rinsing. Sometimes its harder moving bits though.
Tried a set of brass ones off flea bay and they were rubbish.
A thing to note. I rinse on the glass. If I rinsed on the glass, I think I would use pencil jets.