How to delete browsing history from BT home hub?

Planning surprise for mum, used my iPhone to access Wi-Fi on their BT home hub, don't want any chance of them finding out what I'd been looking at even though I was using my iPhone.
If this data is stored on their home hub box, can it be erased? Or am I safe?

See this i think it surely helps you:
http://btbusiness.custhelp.com/app/answers/detail/a_id/7229/~/how-can-i-clear-my-browser-cache%3F