do I have to buy all of one or can I combine the two and still get the ecbs?

also, does anyone know if I have to purchase the clean and clear all in one transaction?

I believe it is like all others and you can split it up all I know is if you don't want to get stuck with a $20 ECB then don't do them both in one transaction. I hadn't looked at the ad on Sunday and decided to stop in and saw the tags and thought oh I will get those! I now have one $20 ECB instead of 2 $10

But any way you should be able to get them separate orders. I haven't known of a time that you had to get it all at once. But I am still fairly new to it all.

You can purchase qualifying items in separate transactions. Towards the bottom of your receipt, you will see that it keeps track of the deals that you have done or are working on. It will say how much you have towards a deal and how much more you still need.