I've really got no idea, sorry.

If you were going to use cloth then maybe use some flushable liners to prevent as much of the poo from contacting the nappy as possible and then flush it. I'd give them a good rinse in hot water also and then perhaps wash at the end of the day instead of waiting for a full load so they're not sitting around.
She had no idea how long the virus could be in her poo for? I would assume it would be in the literature that comes with the vaccine. I'm sure the old polio one (sabin) was 48 hours but I could be remembering wrong.