We pack and export color bell peppers to the United States; originally we didn't wash our peppers, we only cleaned them. Then we began to wash them with chlorine in water, to 150 ppm. Now we are thinking that immersing peppers in a tank could better clean the residues on them. (J.P.M.)
It is preferable to do a spray wash just as you are doing rather than a dump tank. I assume you are also using soft brushes in the process which will facilitate surface cleaning. With a single use spray wash you can ensure that the water that comes in contact with the peppers is always clean. That is very difficult to do in a dump tank as a few peppers with decay-causing pathogens can contaminate the whole tank. In addition, water uptake through small cracks (blossom end) can occur and cause decay problems. Food safety concerns also dictate that a spray wash is better than a dump tank for the same reasons, especially the cross-contamination aspect. The residues you refer to are the inert components of the pesticide sprays, those should be easily removable with a spray wash and some soft brushes.