I use these at work because I don't like the weak office coffee. (And because a lot of the aromatics leave coffee within 60 seconds of grinding -- but that's the subject for another thread!) My co-workers call my coffee "Mud".
I ruined lots of them at first due to fine grinding. Fine (or even "drip" ground) coffee clogs the filter and makes a kind of a muddy slurry in the filter. You can try to harass it and stir it and watch it go through the filter two drops at a time, but eventually the glue on the filter will fail and you get a big mess.
The answer for me has been to grind coarse. Not quite "french press" coarse, but getting there. This creates a nice clean cup which can easily run through the filter paper.
Next, pour the water in two stages. Fill the filter once, then let it drain out. (Stir the slurry a bit to make sure everything gets wet.) Once the filter has "drained", you can do the full pour.
Also, use a burr grinder rather than a blade grinder. Commercial grinders are all burr grinders. Blade grinders give uneven particle sizes, meaning that you get a bunch of boulders giving you weak acidic coffee and a bunch of powder clogging up your filter. A blade grinder also heats the beans; actually re-roasting them and destroying all the hard work the professional roaster put into them to make them perfect. Blade grinders should be outlawed!
...I am from a coffee city; kind of like the Seattle of Canada...