[Shodo]

If you're limiting yourself to solo, then your best options are probably the same ones available to my paladin - i'm sure there are some others you could fear kite but I don't have experience with those.

Basically, I've found the following cash camps that are easily soloable with a level 60 knight:

Lguk - Ghoul Arch Magus - Shining Metallic Robes ~2k (rare spawn, rare drop)
Lguk - Frenzy - FBSS ~4k (rare spawn, rare drop, harder camp)
Lguk - Ghoul Lord - SBSS and SSoY ~500/ea (uncommon spawn, guaranteed drops, harder camp)
Lguk - Ghoul Supplier - TBB ~2k (rare spawn, rare drop)

Kaesora - Xalgoz - Staff of the Dreaded Gaze ~25-30k (uncommon spawn, ultra rare drop, can also sell HS key MQs)

Droga - Soothsayer Whateverthefuckhisnameis - Earring of Essence ~3k (rare spawn, rare drop)
Droga - Chief and Bodyguard - Idol of the Thorned ~3k and Gauntlets of Potence ~1.5k (uncommon spawns, rare drops)

Sol A - Grab an Earthshaker and a damage shield and pull 25 goblins. AE/slash them down and then sell the ore at the druid rings. ~500pp per hour depending on ore drops and if there are people xp'ing in the zone.

There are other more challenging camps you can attempt like soloing nameds in HS but the above are all very consistent and doable.
Downsides: Most are camped quite often, and the cash isn't stellar - expect to get a single ~2-3k pp drop every 4-6 hours depending on your luck.
Upsides: All of the camps are stupid easy, with the exception of ghoul lord, and have relatively long respawn timers (especially Lguk), so you can clear the camp in 2-3 minutes then Netflix for the next 20-25 mins.