Sorry for the delayed reply but work days are completely unpredictable.

So I cleaned off the lever where it meets the slave cylinder's piston/ball. It was pretty messy in there. I cleaned it with a little brake fluid cleaner and applied, sparingly, grease only around the point of contact. It seemed as if the whole shaft was completely over greased. I'd imagine that the grease would be completely nasty and dirty, which it was. If it means anything, the rubber boot covering the shaft had split. I don't know if that has any implications.
I just topped off the reservoir yesterday.

What should I look for next?

 

Keep an eye on it, look for FRESH leakage & then you need to figure out where it's leaking from.

The boot is only semi-important. Later years Accords its more open. Just sorta keeps dirt out, but it never was airtight.

One possibility is that someone went nuts with grease on that ball & socket. That would just confuse the search for the real leak.

More likely(?) is the slave cylinder is leaking brake fluid out alongside the piston rod. It picks up dirt & turns into greasy sludge. You'll want to catch it leaking before it gets so bad you can't tell the source.