Or if you have the parts (i.e. 2.5 to 3.5 inch adapter and a suitable PC) you could try to fsck it in a regular PC with lots of memory.

There's nothing special in the empeg fs that should prevent this, is there?

Means pulling apart the empeg and the computer of course, so not the most practical route. And doesn't help the next time it happens.

Turning on swap only on the other drive won't help if memory is lacking. It would make the process quicker if there was enough memory.