this might raise the chances of the plant hermying... think about nature, when/where would you ever see 24 hours of night? ive heard of doing this AFTER flowering, right before harvesting, cus it apparently makes your plants think they are dying so they freak out and crystallize alot - which might also be bullshit, but im pretty damn certain putting your plants in 24 (especially 48...wtf) hours of dark before flowering isnt gonna have any positive effect. i dont think it would hurt yield or quality, infact it might help "reset" the plant cus ive had a pro grower friend mention something about this.
i really dont know if id risk it though, its always best to get scientific backup before doing something that might confuse/hermy/stress your plants.