How about a current clamp? They are bit expensive to buy but I think you can make one cheaply. It's also a very safe way to make the measurement. Just throwing out an idea.

 

We are starting to communicate.

If you have the meter wired into the circuit when you first apply power, then no problem. If you try to connect the meter afterwards then it is dangerous for a couple of reasons.

 

Yeah, I could buy an amp clamp, but I don't want since I have this wonderful multimeter (for me) and I want to use it.

OK Dick, hahahaha, this is worse than a mute person trying to say to a deaf person that his blind friend saw a delinquent coming.

Yes, of course I have the meter wired to the cut neutral cable (notice that cut does not mean open since the meter closes it again, hahahaha), the paint I made is water clear I think.

What do you mean by "connecting it afterwards"?

 

You :

"Now, what I am looking for is a hand-free thing to insert the leads in the cut neutral wire. Any ideas of what can I use?"​

That makes me think you want to connect the meter to neutral after the other wires are connected -in other words after the heater is connected to 240 VAC. That would not be good.

 

I think the current clamp can be connected to the multimeter and the multimeter would display the RMS value of the measured current, you would need the conversion impedance factor of the current clamp to convert the measured voltage on the multimeter to the current through the clamp. If you get a BNC to banana(male) converter.