Yes you can use a stake and slowly straighten the trunk. I typically use a bamboo stake, steel rebar,, or electrical conduit and then over several weeks progressively tighten to the desired position. Be careful about exerting too much pressure with twine or string.

A stake definitely detracts from the plant's eye appeal by competing with the plant for your eye, and sometimes straight trunks are boring. Also, the swaying of a tree or woody plant in the breeze stimulates production of lignin - a natural polymer which makes branches and stems stiff/ woody. Staking it limits the natural strengthening it would otherwise get.

If what you're looking for is having the center of the foliage mass directly above the center of the pot, that can be easily achieved by repositioning the plant in the pot. For a preview of how that would look, hold the pot in both hands, reposition the pot so the foliage mass is directly above the pot and turn the plant so you can view the composition from all sides.

By repositioning the plant you can eliminate need for the stake and will be able to use the plant's phototropic response (tendency to lean toward the light) to create additional soft curves.

A little off topic, but these before and after images of Suthin's initial work of what will be a long sequence highlights his intent to reposition the tree in a pot at the same angle shown in the after image.

The position of the pot shows what an ambitious and lengthy process he's planning. By contrast, what you'd need to do would take only minutes.

Al

Oh,its easy to stake them up. Stems are actually rubbery.