How to open true Zero Balance Account with HDFC bank

[JosephJohn]

I have 3 inter related questions below:
Ques1)- If I want to open a zero balance account in HDFC Bank (not BSBDA), can I open a "Demat Account" in HDFC and get a zero balance account in the bank??
If yes, then what will be the hidden charges or maintenance charges of "Demat Account"? And if there any more charges applicable then please tell.

Ques2)- And can this Demat method work in any bank?? (if it is working)

Ques3)-What are the differences between a bank account opened through a Demat account and a normal bank account?

Ques4)- If any charges are being imposed due to "Demat Account", can we close the "Demat Account"? So that we can just use a zero balance account.

 

[sovrenn]

There is an actual cost (KYC, documentation, eSign, human verification, etc.) that is incurred while opening an account. If there was no account opening fee to recover the cost, the business could implicitly be pressured to get a customer to transact to recover that cost,'' said Zerodha in its update.