Good tips. Your glass coated thermistor will last up to 300C so yes you can blow it out. I did that a few days ago as well because of a few errors in repetier host (software) and had to replace the thermistor. I am holding it in place with some painter's tape. There is also cotton insulation tape you can use. Use a resistance meter to measure the sensor; if its value randomly changes you need to replace it.

If you have a few days, you can soak the nozzles in MEK, it's quite aggressive but dissolves the PLA. What I find is that most often, temperature changes along with mechanically pushing filament in and pulling it out cleans the nozzles as well.