I have a bunch of ISO/ASA 100 (Shanghai GP3) in the fridge I'd like to mess around with on my RB67. (I have no slow speed film atm at home - and I have to travel a few hours to a capital city to get 120 film, or buy it online). Developing at home in Xtol. Anyway I'd like to do some slow shutter speeds in full daylight. I have an ND8 filter and an ND8 grad, and thats it. And I can shoot at f/22 (or f/32 fpr 12mp equiv detail). I've noticed Xtol doesn't like short development times, but say if I want to pull to ISO 10 what should I do? and if pull-developed correctly what effect will this have on the image? Blow the grain out? Consider the slowest film I have is 100, and I oly have one ND8 filter (and the grad which might be useful to stack to keep the sky down in some shots) and f/32, what's my best option for processing the film since I want to expose it for a few seconds?