When he says crush washer, are you actually selling him a transmission fill and drain plug washer that is a crush-type?
My idiot dealer tried to confuse me the last time I tried to purchase the transmission drain and fill washers. He tried to sell me copper crush washer (like for the engine oil drain plug), but I knew from previous experience that the transmission and differential plugs use just a flat metal washer. I went back later with part numbers to make it easy for their low capacity brains.
The engine oil drain plug washer is Part #11026-JA00A
Need one (1) washer for fluid change
The transmission drain and fill plugs are Part #11026-4N200
Need two (2) washers for fluid change
The differential drain and fill plugs are the same as for the transmission. Of course, Nissan tried to make this as confusing as possible by naming them Transmission Drain Plug
Gasket and Differential Drain Plug
Washer even though they are the same part.