you can generally make ink flow better with some soap bubbles added to ink. But it's not a long term/permanent solution because it's tiresome doing it for each refill.

I also take a razor blade to chinese pens to make them wetter. The nib slits are tighter than western nibs so I spread tines with razor blade. I also run razor blade in the feed channel if I can remove feed. Both to widen/deepen channel, and because again the chinese feeds aren't "clean" since there are spurs on the plastic sometimes. But these chinese pens are on cheap side <$10 so if I ruin a feed/nib, I'm not too sad over it since the pen wasn't writing how I wanted so I wouldn't have used them otherwise.