Way to discharge solenoid without (heated) resistors?
When you see the rating of a resistor it is for peak dissipation, often if you are just going to be discharging resistors on an irregular basis you do not need to have high wattage resistor as your resistors are really not getting many joules of energy. It is high wattage, but a very short time.

Do some testing with lower wattage resistors for discharge, you will find they can dissipate much more then needed. The issue in your current circuit is that your resistors are forming the limiting for your solenoid all the time, meaning a lot of heat. The major point that is invalidating your simulation is the lack of a resistance for your solenoid. You should look up the resistance of your solenoid as it will significantly resist current flow on its own.