Although I would not find it in the least bit difficult to keep thoroughly clean and fresh for weeks without shower or bath I think there is another issue here. Many festival campsites are now charging more than commercial sites. We camp regularly on sites charging around £8 per unit (this is for five of us) and these sites have showers, washers, clubhouse, kids entertainment etc. Festivals are charging anything up to £6 per night per person for which we should at very least expect good quality shower blocks and toilets.