Mixing should be done automaticly with option to set a limit for manual control (for example deposits about 1 BTC will be done manually).
Please send me PM if you have a working script and a link I can check.
Thanks.
I guess you know that is a very risky deal. Buying mixing script from an unknown person over the internet you can never know for sure that a script is clean without malicious code. If there things going wrong, no one will blame the script owner, it will only be your fault.
Also if there any bug, you will have to know how to correct it. Otherwise, everything is worthless to you.
So, either OP has to be an high skilled dev by himself or he would need to hire a coder to audit the script first, that would be the only solution after buying a mixer script from a random person.