Deleting single entry on Xively

I have read the article on how to delete an entry from a datastream; however, I don't know how to issue a DELETE command via PHP, or any other method for that matter. In addition, the API reads you must know the timestamp of the event to delete. On this issue I can see the graph illustrating a drop in sensors (my own doing) but when I poll the JSON via browser I can't find the entry, even specifying interval=0 which should return the raw data. Further, there seems to be no forum on Xively for community-based support. I sent off an email, not holding my breath though.

So, I can see the issue on the graphs, I can't find the entry timestamp, and even if I had that I couldn't issue the DELETE command. Open.Sen.Se lets me see the feed events and delete them with one click. Is there really no similar simple function on Xively?

Ant tips on any if the issues I have are welcome. TYIA