You mean 'these are bananas'. Sorry, wrong thread!
I was hoping to try out some obscure lenses with my Speed Graphic but the shutter was beyond repair so I may try the darkslide trick myself. If I remember correctly, the Jim Galli method involved two dark slides held at an angle with a gap in between and moved from one in front of the lens to the other. This would be for a fast shutter speed though. For six seconds, one would do fine.
I hate not being able to get out but I haven't resorted to photographing bananas..... yet!