snakes dont have the same digestive system like warm bloodeds that have to poo at least every day. my female mojave ball only poos after shedding (every 2-3 months). i dont think it's that they're intentionally holding it more so then they just dont 'build' up enough poo to go as often.
think of it like this, if we only ate once a week, or every 10 days, or every 2 weeks even, we wouldnt be pooing that often either.