It will take f8888 ages - sub it to a ball cleaner. We did one at Madplay in Greenhithe, took forever to bag them up and the bloke turned up with a machine that sucked them up, forced them through a solution with a brush set up and blew them out. It took him most of a day. The empty ball pool was full of dust, plasters, socks and every other thing kids have. There was a machine advertised in the INPA - TIPE magazine this month. You will be sick of the sight of balls - BE WARNED