I'm a little hazy on the exact levels that I did these, but two places you could try are Mines of Nurga and Crystal Caverns. Both places are low traffic (especially Nurga) and I had a lot of fun charm soloing in them. Nurga has several different flavors of caster mobs which makes for some exciting fights. CC is also nice because it has a town in zone that you can vendor and bank at with illusions. You can't bind in CC though, so you have to bind in EW either outside the orc fort or right at the teleporter. If you bind at the teleporter, make sure you're ready to click yourself into CC after gating or dying because there's a roaming orc that paths by the teleporter sometimes. Check out Tecmos' videos here for charm solo ideas and guides for the various locations:
https://www.youtube.com/channel/UCkZ...YEE9Y-_FTW4HZg