I haven't ventured this side of Little Forest Plateau myself, but based an a trip we did down Gaol house pass to the Clyde and then back up Dunmal creek to Talaterang and back to Mt Bushwalker I would suggest any "off track" walking in this area is really difficult. The scrub is impossible and the creeks are also very difficult and require rope.
Getting up from the Clyde to Talaterang was a *&%$#! hard day and we ended up camping wherever we could find an open area on Taleterang when we ran out of daylight and couldn't make Gadara Point.
I note this great trip report, which seems to indicate getting to the caves was reasonably easy but trying to do a circuit not so good - certainly lines up with all the experience I've had this side of the budawangs:
http://bushwalk.com/forum/viewtopic.php?f=47&t=16871I noted that there were some photos of the cave and the pass down Rusden head in below link. Looks like a great cave.
https://www.meetup.com/en-AU/South-Coas ... 224870227/