I just stumbled on an idea for how to repair white gel pens at Captain Crafter's Blog.
I haven't tried it yet, so I can't say how well it works, but it looks cool so i thought I'd share.
Other tips I have heard that work fairly well-
1.take the pen apart and blow hard into the barrel of the ink insert like it is a straw. I have tried this one & it works but sometimes it only works temporarily.
2. Shake the pen hard as if it were a Mercury thermometer- use a snapping motion with the tip pointed down. I have tried this one also and it too seems to work temporarily, but not all the time. I guess it depends on how old the pen is or how long it has been since it was last used.
To me, it seems the best thing to do is avoid the pen clogging up altogether, and the best way to avoid that is to use it regularly :)
That's it for now- I have some more pictures to post later tonight when I have more time!