I have maneged to torch it all out, now I'm good to print.

I wouldn't recommend soaking the bottom part of the extruder it might  mess the thermistor up. Did you seperater the extruder's throat from the bottom end?

You can soak it in acetone for months. There is nothing on it that acetone can harm other thsn the unwanted ABS. The thermistor is composed of glass, copper wire, and teflon sleeving. All of these will not be affected by acetone in any way. I soaked mine nearly 20 times in the course of a year due to poor filament.

Now if this happens with PLA you will have to torch it out or buy a new head. There is no solvent other than Tetrahydrofuran that will dissolve PLA. I would caution you strongly to read the MSDS on that chemical and consider carefully if your home and life are worth the price of a new head.

The only way to fix this problem is to take the extruder apart and soak it in acetone or torch it out

I've trşed torching it and took out most of the material. Still not enough.

If I soak the nozzle in acetone, will it destroy the silicones over the connections?

I've recently bought a da vinci printer, i use a hacked cartidge and have been printing about 120 hours with ABS.

Last night, 3rd party cartidge got stuck on its stand, and broke. I tried to load the filament again but  but could not.

Than, I took the extruder out and saw that broken part was below the extuder motors discs. So it couldn't push the broken part of the filament. I tried to take out the broken filament, while the nozzle is hot, but it did not work either. The filament broke again leaving a small piece in the canal going to nozzle.

I even tried pushing it manually with a piece of filament, of course when the nozzle is hot, it did not work either. I tried cleaning the nozlle with thinf wires that comes with it, it did not work.

What is the problem here ? How can i fix this?

Thanks for all the answer