I have tried the CCI brand shot shells in my Ruger 10/22 and they would not cycle the action, I would have to shoot one round, cycle the action manually then repeat. I would guess that these won't cycle the action of your 22/45 also, now if I wanted to use these, I would shoot them out of a revolver - for faster follow up shots when needed. You may want to try other larger caliber shot shells, again in revolvers, bigger caliber = more shot = more effective pest control!!
I believe Speer still makes shot shell capsules for reloading, I have some in .44 caliber. Little clearish plastic cups you fill w/your choice of shot size, press in a lil' plastic cap, then load them just like a bullet. I haven't tried them yet myself, but I'm sure you can get reloading data from Speer also. (We just don't have many / any sankes up here in Alaska, I imagine there are some rats in a few port towns, but "basically" none to speak of up here.
Hope this helps, good luck killin' them rats, gosh I hate them!!
Del