I have been servicing a customer for quite some time now and we were asked to service a interior courtyard of a exclusive home. We have done the interior courtyard trees, shrubs and all for 12 years but here is the issue. There is a fountain in the middle of this Venetian designed courtyard. A cylindrical fountain made of Pennsylvania stone is erected with a Bronze Cherub fountain inside. This bronze statue was hand made by a Artist somewhere in Dallas Texas and was told that the statue is worth 25,000.00. Each Cherub is playing a specific instrument..............a flute and horns. The statue is stopping up from the pump system underneath this heavy sculpture. The plumbing is brazed together and the statue has to be hoisted with something more than we can handle. The sculpture was installed in this home as it was being built so going through any hallways or door ways isn't allowed. We need to unstop the instruments as the water isn't flowing through each figure as the client wants it to do. What bronze safe cleaners would you suggest us using as this is not a child's game of using something to corrode this master piece of artwork. What will break up the sludge and hard water deposits and not hurt this sculpture??????? Please, serious responses needed!!!!!