Can I use my SPX-RB1 Pressure Washer accessory with the soap dispenser that is built into my SPX Pressure Washer? Yes, the SPX-RB1 Pressure Washer accessory is compatible with the on-board soap bottle on your SPX Pressure Washer. Related articles Why is my SPX-FC34 not dispensing detergent? Why is my SPX-FC34-MAX not dispensing detergent? Will my SPX Pressure Washer accessory work with the on-board soap bottle on my unit? Which adapter do I need to use my SPX-UB1 accessory with my SPX Series Pressure Washer? Can I run the unit for a long period of time?