Can a flush kit tee be used as a heater control valve

Are you trying to block off the heater or turn it on/off. If the former then you might be able to use it to connect the two hoses and bypass the core. If you are thinking of using it like a valve. Then no, it is an open T with no valving inside.

I just need heat and a running car.

Okay you currently have a bad control valve and just want to remove it and let the coolant flow? If that is the case then you could use it.

I was reading the question as "I need a control valve" Sorry.