Hi David,
You are right. First, you have to list past batches. You would need to order that list by timestamp desc, in order to have the last one and going through the past ones. Then, you could use API services to delete specific batch's.
If you are looking to do it for data cleansing in the data storage, once an Adobe Support Architec told me that this storage only counts for what is in the profile store and not data like. Now the only benefit I'll see is to decrease the processing time when querying a dataset.
Best,
Renato
