Creating a low (90-250F) temperature-controlled soldering iron (or modifying a higher temp one to get lower temps)
You can get a (TRIAC) light dimmer and wire it in a box outlet. Use a &lt;25W small light in parallel to monitor the power input in case of inadequate load, and hysteresis effects.

You can calibrate it with power input and temperature output or set by trial and effect.

Although this is not regulated the temerpature could be proportional to % power input. (except for hysteresis)

If cooled rapidly it will return to normal temperature in a minute or so.

You may want the chisel edge or round 1/16" screw on tip with a 15W or 25W heater.