Its not a good idea to put your address on an open site and you have to come back on site to check your replies.

You could, but the wilder forms of Verbascum grow very big - I have one that would have been over 8' tall, if it hadn't flopped over. And that's where the problem lies - it needs to be a very big pot or tub and it may well get very top-heavy and fall over, tub or pot and all.

I think you'd be better off picking one of the smaller varieties of Mullein to grow in a container.