Trying to get mud/windslicer shot for Balthier, but I can't find any silver liquid. I know they drop from Hectayes and Foobars, but I can't find those either. Where are they?

Foobars are in the nabreus deadlands. Hecteyes I believe are in the tomb of raithwall after you defeat the first demon wall.

Wait a sec --- I thought the Hecteyes was in the Henne Mines, in one of the areas that only becomes accessible after the Geomancer of the Garif opens it for you because you have enough espers. Or am I thinking of something else?

Agent, you are correct. There are also some Hecteyes in Draklor Laboratory, but you have to completely case the place to find them, as they are in the room that probably requires the most effort to reach. And you can only visit once, so ignore my babbling.

So at level 41, the best place to get them would be the Nabreus Deadlands. Thanks!

Yeah, I'd have to say so. At Level 41, you'd have pretty much no chance of surviving that area of the Henne Mines, even if you had enough espers to get it opened up, which I'm guessing is almost certainly not the case.

Definitely not, only optional esper I've acquired so far is Adrammalech. I plan on trying for Zalera and maybe Cuchulainn once I finish Giruvegan though.

Draklor, thats right. Sorry! I knew I'd heard the name somewhere, and as I've haven't gone to the extra part of henne...